"Except ye believe ye shall not understand" - Isaiah 7:9 (LXX)
"The LORD looked down from heaven upon the children of men, to see if there were any that did understand, and seek God." - Psalm 14:2 (KJV)
"God looked down from heaven upon the children of men, to see if there were any that did understand, that did seek God." - Psalm 53:2 (KJV)
"As it is written in the law of Moses, all this evil is come upon us: yet made we not our prayer before the LORD our God, that we might turn from our iniquities, and understand thy truth." - Daniel 9:13 (KJV)
"Even the Spirit of truth; whom the world cannot receive, because it seeth him not, neither knoweth him: but ye know him; for he dwelleth with you, and shall be in you." - John 14:17 (KJV)
"My son, if thou wilt receive my words, and hide my commandments with thee; so that thou incline thine ear unto wisdom, and apply thine heart to understanding; yea, if thou criest after knowledge, and liftest up thy voice for understanding; if thou seekest her as silver, and searchest for her as for hid treasures; then shalt thou understand the fear of the LORD, and find the knowledge of God." - Proverbs 2:1-5
"Ye are my witnesses, saith the LORD, and my servant whom I have chosen: that ye may know and believe me, and understand that I am he: before me there was no God formed, neither shall there be after me." - Isaiah 43:10 (KJV)
"Through faith we understand that the worlds were framed by the word of God, so that things which are seen were not made of things which do appear." - Hebrews 11:3 (KJV)
But the husbandry is twofold,— the one unwritten, and the other written. And in whatever way the Lord's labourer sow the good wheat, and grow and reap the ears, he shall appear a truly divine husbandman. "Labour," says the Lord, "not for the meat which perishes, but for that which endures to everlasting life." [John 6:27] And nutriment is received both by bread and by words. And truly "blessed are the peace-makers," [Matthew 5:9] who instructing those who are at war in their life and errors here, lead them back to the peace which is in the Word, and nourish for the life which is according to God, by the distribution of the bread, those "that hunger after righteousness." For each soul has its own proper nutriment; some growing by knowledge and science, and others feeding on the Hellenic philosophy, the whole of which, like nuts, is not eatable. "And he that plants and he that waters," "being ministers" of Him "that gives the increase, are one" in the ministry. "But every one shall receive his own reward, according to his own work. For we are God's husbandmen, God's husbandry. You are God's building," 1 Corinthians 3:8-9 according to the apostle. Wherefore the hearers are not permitted to apply the test of comparison. Nor is the word, given for investigation, to be committed to those who have been reared in the arts of all kinds of words, and in the power of inflated attempts at proof; whose minds are already pre-occupied, and have not been previously emptied. But whoever chooses to banquet on faith, is steadfast for the reception of the divine words, having acquired already faith as a power of judging, according to reason. Hence ensues to him persuasion in abundance. And this was the meaning of that saying of prophecy, "If you believe not, neither shall you understand." [Isaiah 7:9] "As, then, we have opportunity, let us do good to all, especially to the household of faith." [Galatians 6:10] And let each of these, according to the blessed David, sing, giving thanks. "You shall sprinkle me with hyssop, and I shall be cleansed. You shall wash me, and I shall be whiter than the snow. You shall make me to hear gladness and joy, and the bones which have been humbled shall rejoice. Turn Your face from my sins. Blot out mine iniquities. Create in me a clean heart, O God, and renew a right spirit in my inward parts. Cast me not away from Your face, and take not Your Holy Spirit from me. Restore to me the joy of Your salvation, and establish me with Your princely spirit."- Clement of Alexandria (about A.D. 150 - 215), Stromata, Book I, Chapter 1
It is clear, then, that the truth has been hidden from us; and if that has been already shown by one example, we shall establish it a little after by several more. How entirely worthy of approbation are they who are both willing to learn, and able, according to Solomon, "to know wisdom and instruction, and to perceive the words of wisdom, to receive knotty words, and to perceive true righteousness," there being another [righteousness as well], not according to the truth, taught by the Greek laws, and by the rest of the philosophers. "And to direct judgments," it is said— not those of the bench, but he means that we must preserve sound and free of error the judicial faculty which is within us— "That I may give subtlety to the simple, to the young man sense and understanding." "For the wise man," who has been persuaded to obey the commandments, "having heard these things, will become wiser" by knowledge; and "the intelligent man will acquire rule, and will understand a parable and a dark word, the sayings and enigmas of the wise." [Proverbs 1:2-6] For it is not spurious words which those inspired by God and those who are gained over by them adduce, nor is it snares in which the most of the sophists entangle the young, spending their time on nought true. But those who possess the Holy Spirit "search the deep things of God," [1 Corinthians 2:10] — that is, grasp the secret that is in the prophecies. "To impart of holy things to the dogs" is forbidden, so long as they remain beasts. For never ought those who are envious and perturbed, and still infidel in conduct, shameless in barking at investigation, to dip in the divine and clear stream of the living water. "Let not the waters of your fountain overflow, and let your waters spread over your own streets." [Proverbs 5:16] For it is not many who understand such things as they fall in with; or know them even after learning them, though they think they do, according to the worthy Heraclitus. Does not even he seem to you to censure those who believe not? "Now my just one shall live by faith," [Habakkuk 2:4] the prophet said. And another prophet also says, "Unless you believe, neither shall you understand." [Isaiah 7:9] For how ever could the soul admit the transcendental contemplation of such themes, while unbelief respecting what was to be learned struggled within? But faith, which the Greeks disparage, deeming it futile and barbarous, is a voluntary preconception, the assent of piety— "the subject of things hoped for, the evidence of things not seen," according to the divine apostle. "For hereby," pre-eminently, "the elders obtained a good report. But without faith it is impossible to please God." Others have defined faith to be a uniting assent to an unseen object, as certainly the proof of an unknown thing is an evident assent. If then it be choice, being desirous of something, the desire is in this instance intellectual. And since choice is the beginning of action, faith is discovered to be the beginning of action, being the foundation of rational choice in the case of any one who exhibits to himself the previous demonstration through faith. Voluntarily to follow what is useful, is the first principle of understanding. Unswerving choice, then, gives considerable momentum in the direction of knowledge. The exercise of faith directly becomes knowledge, reposing on a sure foundation. Knowledge, accordingly, is defined by the sons of the philosophers as a habit, which cannot be overthrown by reason. Is there any other true condition such as this, except piety, of which alone the Word is teacher? I think not. Theophrastus says that sensation is the root of faith. For from it the rudimentary principles extend to the reason that is in us, and the understanding. He who believes then the divine Scriptures with sure judgment, receives in the voice of God, who bestowed the Scripture, a demonstration that cannot be impugned. Faith, then, is not established by demonstration. "Blessed therefore those who, not having seen, yet have believed." The Siren's songs, exhibiting a power above human, fascinated those that came near, conciliating them, almost against their will, to the reception of what was said.- Clement of Alexandria (about A.D. 150 - 215), Stromata, Book II, Chapter 2
5. That the Jews could understand nothing of the Scriptures unless they first believed in Christ- Cyprian of Carthage (died about A.D. 258), Treatise 12, First Book, Section 5 (heading of section is accurate but authorship may not be original)
In Isaiah: "And if you will not believe, neither will you understand." [Isaiah 7:9] Also the Lord in the Gospel: "For if you believe not that I am He, you shall die in your sins." [John 8:24] Moreover, that righteousness should subsist by faith, and that in it was life, was predicted in Habakkuk: "Now the just shall live by faith of me." [Habakkuk 2:4] Hence Abraham, the father of the nations, believed; in Genesis: "Abraham believed in God, and it was counted unto him for righteousness." [Genesis 15:6] In like manner, Paul to the Galatians: "Abraham believed in God, and it was counted unto him for righteousness. You know, therefore, that they which are of faith, the same are children of Abraham. But the Scripture, foreseeing that God justifies the heathens by faith, foretold to Abraham that all nations should be blessed in him. Therefore they who are of faith are blessed with faithful Abraham."
Now as for the question, how any single thing came into existence, we must banish it altogether from our discussion. Even in the case of things which are quite within the grasp of our understanding and of which we have sensible perception, it would be impossible for the speculative reason to grasp the "how" of the production of the phenomenon; so much so, that even inspired and saintly men have deemed such questions insoluble. For instance, the Apostle says, "Through faith we understand that the worlds were framed by the word of God, so that things which are seen are not made of things which do appear [Hebrews 11:3]." He would not, I take it, have spoken like that, if he had thought that the question could be settled by any efforts of the reasoning powers. While the Apostle affirms that it is an object of his faith that it was by the will of God that the world itself and all which is therein was framed (whatever this "world" be that involves the idea of the whole visible and invisible creation), he has on the other hand left out of the investigation the "how" of this framing. Nor do I think that this point can ever be reached by any inquirers.- Gregory of Nyssa (about A.D. 335 - 394), On the Soul and the Resurrection
Then, too, what is that immaterial and ethereal empyrean, and the intermediate air which forms a wall of partition between that element in nature which gives heat and consumes, and that which is moist and combustible? And how does earth below form the foundation of the whole, and what is it that keeps it firmly in its place? What is it that controls its downward tendency? If any one should interrogate us on these and such-like points, will any of us be found so presumptuous as to promise an explanation of them? No! the only reply that can be given by men of sense is this:— that He Who made all things in wisdom can alone furnish an account of His creation. For ourselves, "through faith we understand that the worlds were framed by the word of God," as says the Apostle [Hebrews 1:2].- Gregory of Nyssa (about A.D. 335 - 394), Answer to Eunomius' Second Book
Faith needs a generous and vigorous soul, and one rising above all things of sense, and passing beyond the weakness of human reasonings. For it is not possible to become a believer, otherwise than by raising one's self above the common customs [of the world].- Chrysostom (about A.D. 347 - 407), Homily 22 on Hebrews, at Hebrews 11:3.
I Believe, therefore, is placed in the forefront, as the Apostle Paul, writing to the Hebrews, says, "He that comes to God must first of all believe that He is, and that He is a rewarder of those who believe in Him." The Prophet also says, "Except ye believe, you shall not understand." That the way to understand, therefore, may be open to you, you do rightly first of all, in professing that you believe; for no one embarks upon the sea, and trusts himself to the deep and liquid element, unless he first believes it possible that he will have a safe voyage; neither does the husbandman commit his seed to the furrows and scatter his grain on the earth, but in thebelief that the showers will come, together with the sun's warmth, through whose fostering influence, aided by favouring winds, the earth will produce and multiply and ripen its fruits. In fine, nothing in life can be transacted if there be not first a readiness to believe. What wonder then, if, coming to God, we first of all profess that we believe, seeing that, without this, not even common life can be lived. We have premised these remarks at the outset, since the Pagans are wont to object to us that our religion, because it lacks reasons, rests solely on belief. We have shown, therefore, that nothing can possibly be done or remain stable unless belief precede. Finally, marriages are contracted in the belief that children will be born; and children are committed to the care of masters in the belief that the teaching of the masters will be transferred to the pupils; and one man assumes the ensigns of empire, believing that peoples and cities and a well-equipped army also will obey him. But if no one enters upon any one of these several undertakings except in the belief that the results spoken of will follow, must not belief be much more requisite if one would come to the knowledge of God? But let us see what this "short word" of the Creed sets forth.- Rufinus (about A.D. 345 - 410), Commentary on the Apostles' Creed, Section 6
If we have understood this, thanks be to God; but if any has not sufficiently understood, man has done as far as he could: as for the rest, let him see whence he may hope to understand. As laborers outside, we can plant and water; but it is of God to give the increase. "My doctrine," says He, "is not mine, but His that sent me." Let him who says he has not yet understood hear counsel. For since it was a great and profound matter that had been spoken, the Lord Christ Himself did certainly see that all would not understand this so profound a matter, and He gave counsel in the sequel. Do you wish to understand? Believe. For God has said by the prophet: "Except ye believe, you shall not understand." [Isaiah 7:9] To the same purpose what the Lord here also added as He went on— "If any man is willing to do His will, he shall know concerning the doctrine, whether it be of God, or whether I speak from myself." What is the meaning of this, "If any man be willing to do His will"? But I had said, if any man believe; and I gave this counsel: If you have not understood, said I, believe. For understanding is the reward of faith. Therefore do not seek to understand in order to believe, but believe that you may understand; since, "except ye believe, you shall not understand." Therefore when I would counsel the obedience of believing toward the possibility of understanding, and say that our Lord Jesus Christ has added this very thing in the following sentence, we find Him to have said, "If any man be willing to do His will, he shall know of the doctrine." What is "he shall know"? It is the same thing as "he shall understand." But what is "If any man be willing to do His will"? It is the same thing as to believe. All men indeed perceive that "shall know" is the same thing as "shall understand:" but that the saying, "If any man be willing to do His will," refers to believing, all do not perceive; to perceive this more accurately, we need the Lord Himself for expounder, to show us whether the doing of the Father's will does in reality refer to believing. But who does not know that this is to do the will of God, to work the work of God; that is, to work that work which is pleasing to Him? But the Lord Himself says openly in another place: "This is the work of God, that you believe in Him whom He has sent." [John 6:29] "That ye believe in Him," not, that you believe Him. But if you believe on Him, you believe Him; yet he that believes Him does not necessarily believe on Him. For even the devils believed Him, but they did not believe in Him. Again, moreover, of His apostles we can say, we believe Paul; but not, we believe in Paul: we believe Peter; but not, we believe in Peter. For, "to him that believes in Him that justifies the ungodly, his faith is counted unto him for righteousness." [Romans 4:5] What then is "to believe in Him"? By believing to love Him, by believing to esteem highly, by believing to go into Him and to be incorporated in His members. It is faith itself then that God exacts from us: and He finds not that which He exacts, unless He has bestowed what He may find. What faith, but that which the apostle has most amply defined in another place, saying, "Neither circumcision avails anything, nor uncircumcision, but faith that works by love?" Galatians 5:6 Not any faith of what kind soever, but "faith that works by love:" let this faith be in you, and you shall understand concerning the doctrine. What indeed shall you understand? That "this doctrine is not mine, but His that sent me;" that is, you shall understand that Christ the Son of God, who is the doctrine of the Father, is not from Himself, but is the Son of the Father.- Augustine (about A.D. 354 - 430), Tractate 29 on John's Gospel, Section 6
"Out of the mouth of babes and sucklings You have made perfect praise, because of Your enemies." By enemies to this dispensation, which has been wrought through Jesus Christ and Him crucified, we ought generally to understand all who forbid belief in things unknown, [1 Corinthians 2:6-10] and promise certain knowledge: as all heretics do, and they who in the superstition of the Gentiles are called philosophers. Not that the promise of knowledge is to be blamed; but because they deem the most healthful and necessary step of faith is to be neglected, by which we must needs ascend to something certain, which nothing but that which is eternal can be. Hence it appears that they do not possess even this knowledge, which in contempt of faith they promise; seeing that they know not so useful and necessary a step thereof. "Out of the mouth," then "of babes and sucklings You have made perfect praise," Thou, our Lord, declaring first by the Apostle, "Except ye believe, you shall not understand;" and saying by His own mouth, "Blessed are they that have not seen, and shall believe." [John 20:29] "Because of the enemies:" against whom too that is said, "I confess to You, O Lord of heaven and earth, because You have hid these things from the wise, and revealed them unto babes." [Matthew 11:25] "From the wise," he says, not the really wise, but those who deem themselves such. "That You may destroy the enemy and the defender." Whom but the heretic? For he is both an enemy and a defender, who when he would assault the Christian faith, seems to defend it. Although the philosophers too of this world may be well taken as the enemies and defenders: forasmuch as the Son of God is the Power and Wisdom of God by which every one is enlightened who is made wise by the truth: of which they profess themselves to be lovers, whence too their name of philosophers; and therefore they seem to defend it, while they are its enemies, since they cease not to recommend noxious superstitions, that the elements of this world should be worshipped and revered.- Augustine (about A.D. 354 - 430), Exposition on Psalm 8, Section 6
These things you do not understand, because, as the prophet said, "Unless you believe, you shall not understand." [Isaiah 7:9] For you are not instructed in the kingdom of heaven—that is, in the true Catholic Church of Christ. If you were, you would bring forth from the treasure of the sacred Scriptures things old as well as new. For the Lord Himself says, "Therefore every scribe instructed in the kingdom of heaven is like an householder who brings forth from his treasure things new and old." [Matthew 13:52] And so, while you profess to receive only the new promises of God, you have retained the oldness of the flesh, adding only the novelty of error; of which novelty the apostle says, "Shun profane novelties of words, for they increase unto more ungodliness, and their speech eats like a cancer. Of whom is Hymenæus and Philetus, who concerning the faith have erred, saying that the resurrection is past already, and have overthrown the faith of some." [2 Timothy 2:16-18] Here you see the source of your false doctrine, in teaching that the resurrection is only of souls by the preaching of the truth, and that there will be no resurrection of the body. But how can you understand spiritual things of the inner man, who is renewed in the knowledge of God, when in the oldness of the flesh, if you do not possess temporal things, you concoct fanciful notions about them in those images of carnal things of which the whole of your false doctrine consists? You boast of despising as worthless the land of Canaan, which was an actual thing, and actually given to the Jews; and yet you tell of a land of light cut asunder on one side, as by a narrow wedge, by the land of the race of darkness—a thing which does not exist, and which you believe from the delusion of your minds; so that your life is not supported by having it, and your mind is wasted in desiring it.- Augustine (about A.D. 354 - 430), Contra Faustum, Book IV, Section 2
And therefore it is laid down by all the Catholic fathers who have taught perfection of heart not by empty disputes of words, but in deed and act, that the first stage in the Divine gift is for each man to be inflamed with the desire of everything that is good, but in such a way that the choice of free will is open to either side: and that the second stage in Divine grace is for the aforesaid practices of virtue to be able to be performed, but in such a way that the possibilities of the will are not destroyed: the third stage also belongs to the gifts of God, so that it may be held by the persistence of the goodness already acquired, and in such a way that the liberty may not be surrendered and experience bondage. For the God of all must be held to work in all, so as to incite, protect, and strengthen, but not to take away the freedom of the will which He Himself has once given. If however any more subtle inference of man's argumentation and reasoning seems opposed to this interpretation, it should be avoided rather than brought forward to the destruction of the faith (for we gain not faith from understanding, but understanding from faith, as it is written: "Except ye believe, you will not understand" [Isaiah 7:9]) for how God works all things in us and yet everything can be ascribed to free will, cannot be fully grasped by the mind and reason of man.- John Cassian (about A.D. 360 - 435), Conference 13, On the Protection of God, Chapter 18
Now, from here he proceeds, If you do not believe, neither will you understand, a statement not lacking probability; understanding would not be granted by him to people who insult the word of God with unbelief. They ought therefore immediately accept what comes from God and readily agree with what he promises and says. This, in fact, is the way for us to achieve a sound understanding and for our mind to be illuminated by the light of wisdom that comes from him.- Cyril of Alexandria (about A.D. 378 - 444), Commentary on Isaiah, at Isaiah 7:9
Be it mine to look up to your light, even from afar, even from the depths. Teach me to seek you, and reveal yourself to me, when I seek you, for I cannot seek you, except you teach me, nor find you, except you reveal yourself. Let me seek you in longing, let me long for you in seeking; let me find you in love, and love you in finding. Lord, I acknowledge and I thank you that you has created me in this your image, in order that I may be mindful of you, may conceive of you, and love you; but that image has been so consumed and wasted away by vices, and obscured by the smoke of wrong-doing, that it cannot achieve that for which it was made, except you renew it, and create it anew. I do not endeavor, O Lord, to penetrate your sublimity, for in no wise do I compare my understanding with that; but I long to understand in some degree your truth, which my heart believes and loves. For I do not seek to understand that I may believe, but I believe in order to understand. For this also I believe, --that unless I believed, I should not understand.- Anselm (about A.D. 1033 - 1109), Proslogium, Chapter 1
Article 8. Whether faith is more certain than science and the other intellectual virtues?- Aquinas (about A.D. 1225 - 1274), Summa Theologica, Second Part of the Second Part, Question 4, Article 8
Objection 1. It would seem that faith is not more certain than science and the other intellectual virtues. For doubt is opposed to certitude, wherefore a thing would seem to be the more certain, through being less doubtful, just as a thing is the whiter, the less it has of an admixture of black. Now understanding, science and also wisdom are free of any doubt about their objects; whereas the believer may sometimes suffer a movement of doubt, and doubt about matters of faith. Therefore faith is no more certain than the intellectual virtues.
Objection 2. Further, sight is more certain than hearing. But "faith is through hearing" according to Romans 10:17; whereas understanding, science and wisdom imply some kind of intellectual sight. Therefore science and understanding are more certain than faith.
Further, in matters concerning the intellect, the more perfect is the more certain. Now understanding is more perfect than faith, since faith is the way to understanding, according to another version [the Septuagint] of Isaiah 7:9: "If you will not believe, you shall not understand [Vulgate: 'continue']": and Augustine says (De Trin. xiv, 1) that "faith is strengthened by science." Therefore it seems that science or understanding is more certain than faith.
On the contrary, The Apostle says (1 Thessalonians 2:15): "When you had received of us the word of the hearing," i.e. by faith . . . "you received it not as the word of men, but, as it is indeed, the word of God." Now nothing is more certain than the word of God. Therefore science is not more certain than faith; nor is anything else.
I answer that, As stated above (I-II, 57, 4, ad 2) two of the intellectual virtues are about contingent matter, viz. prudence and art; to which faith is preferable in point of certitude, by reason of its matter, since it is about eternal things, which never change, whereas the other three intellectual virtues, viz. wisdom, science [In English the corresponding 'gift' is called knowledge] and understanding, are about necessary things, as stated above (I-II, 57, 5, ad 3). But it must be observed that wisdom, science and understanding may be taken in two ways: first, as intellectual virtues, according to the Philosopher (Ethic. vi, 2,3); secondly, for the gifts of the Holy Ghost. If we consider them in the first way, we must note that certitude can be looked at in two ways. First, on the part of its cause, and thus a thing which has a more certain cause, is itself more certain. On this way faith is more certain than those three virtues, because it is founded on the Divine truth, whereas the aforesaid three virtues are based on human reason. Secondly, certitude may be considered on the part of the subject, and thus the more a man's intellect lays hold of a thing, the more certain it is. On this way, faith is less certain, because matters of faith are above the human intellect, whereas the objects of the aforesaid three virtues are not. Since, however, a thing is judged simply with regard to its cause, but relatively, with respect to a disposition on the part of the subject, it follows that faith is more certain simply, while the others are more certain relatively, i.e. for us. Likewise if these three be taken as gifts received in this present life, they are related to faith as to their principle which they presuppose: so that again, in this way, faith is more certain.
Reply to Objection 1. This doubt is not on the side of the cause of faith, but on our side, in so far as we do not fully grasp matters of faith with our intellect.
Reply to Objection 2. Other things being equal sight is more certain than hearing; but if (the authority of) the person from whom we hear greatly surpasses that of the seer's sight, hearing is more certain than sight: thus a man of little science is more certain about what he hears on the authority of an expert in science, than about what is apparent to him according to his own reason: and much more is a man certain about what he hears from God, Who cannot be deceived, than about what he sees with his own reason, which can be mistaken.
Reply to Objection 3. The gifts of understanding and knowledge are more perfect than the knowledge of faith in the point of their greater clearness, but not in regard to more certain adhesion: because the whole certitude of the gifts of understanding and knowledge, arises from the certitude of faith, even as the certitude of the knowledge of conclusions arises from the certitude of premisses. But in so far as science, wisdom and understanding are intellectual virtues, they are based upon the natural light of reason, which falls short of the certitude of God's word, on which faith is founded.
Article 5. Whether the gift of understanding is found also in those who have not sanctifying grace?- Aquinas (about A.D. 1225 - 1274), Summa Theologica, Second Part of the Second Part, Question 8, Article 5
Objection 1. It would seem that the gift of understanding is found also in those who have not sanctifying grace. For Augustine, in expounding the words of Psalm 118:20: "My soul hath coveted to long for Thy justifications," says: "Understanding flies ahead, and man's will is weak and slow to follow." But in all who have sanctifying grace, the will is prompt on account of charity. Therefore the gift of understanding can be in those who have not sanctifying grace.
Objection 2. Further, it is written (Daniel 10:1) that "there is need of understanding in a" prophetic "vision," so that, seemingly, there is no prophecy without the gift of understanding. But there can be prophecy without sanctifying grace, as evidenced by Matthew 7:22, where those who say: "We have prophesied in Thy name [Vulgate: 'Have we not prophesied in Thy name?]," are answered with the words: "I never knew you." Therefore the gift of understanding can be without sanctifying grace.
Objection 3. Further, the gift of understanding responds to the virtue of faith, according to Isaiah 7:9, following another reading [the Septuagint]: "If you will not believe you shall not understand." Now faith can be without sanctifying grace. Therefore the gift of understanding can be without it.
On the contrary, Our Lord said (John 6:45): "Every one that hath heard of the Father, and hath learned, cometh to Me." Now it is by the intellect, as Gregory observes (Moral. i, 32), that we learn or understand what we hear. Therefore whoever has the gift of understanding, cometh to Christ, which is impossible without sanctifying grace. Therefore the gift of understanding cannot be without sanctifying grace.
I answer that, As stated above (I-II, 68, 1,2) the gifts of the Holy Ghost perfect the soul, according as it is amenable to the motion of the Holy Ghost. Accordingly then, the intellectual light of grace is called the gift of understanding, in so far as man's understanding is easily moved by the Holy Ghost, the consideration of which movement depends on a true apprehension of the end. Wherefore unless the human intellect be moved by the Holy Ghost so far as to have a right estimate of the end, it has not yet obtained the gift of understanding, however much the Holy Ghost may have enlightened it in regard to other truths that are preambles to the faith.
Now to have a right estimate about the last end one must not be in error about the end, and must adhere to it firmly as to the greatest good: and no one can do this without sanctifying grace; even as in moral matters a man has a right estimate about the end through a habit of virtue. Therefore no one has the gift of understanding without sanctifying grace.
Reply to Objection 1. By understanding Augustine means any kind of intellectual light, that, however, does not fulfil all the conditions of a gift, unless the mind of man be so far perfected as to have a right estimate about the end.
Reply to Objection 2. The understanding that is requisite for prophecy, is a kind of enlightenment of the mind with regard to the things revealed to the prophet: but it is not an enlightenment of the mind with regard to a right estimate about the last end, which belongs to the gift of understanding.
Reply to Objection 3. Faith implies merely assent to what is proposed but understanding implies a certain perception of the truth, which perception, except in one who has sanctifying grace, cannot regard the end, as stated above. Hence the comparison fails between understanding and faith.
Is the idea that knowledge of God comes by faith in the Word of God fideism or orthodoxy? I think the latter is the best designation. It is well attested by Scripture and it is not a new idea. It is not that there is no reason to believe, but that some things cannot be reached by bare reason. That's why tools like the Transcendental Argument for the existence of God (TAG) can be a useful negative tool to expose presuppositions, but it cannot be a complete defense of the faith - it cannot be a stand-alone apologetic. Human reason must be subordinated to divine truth, even though human reason is an instrument and tool by which and through which we understand.