(4.) There is a temporary faith, that goes beyond all the former, and is effected by the common operation of the Spirit of God: nor is it merely taken up with the truth of the gospel, but also hath some relish of the goodness and sweetness of it; and hence the stonyground hearers are said to receive the word with joy, Matthew xiii. 20.; yet this belief hath no root, no abiding principle: it is not the faith of the promise that takes place in the children of promise.—Here is the most subtile deceit in the matter of faith: some people may take hold of Christ, as it were, and really get some sap and virtue from him, for their refreshment, and yet never get in to him. They are like the ivy, that grows up by the tree, and clasps about the tree, and draws sap from the tree, and yet grows upon its own root, and is never one and the same with the tree: so here, some professors may receive Christ, in the promise, by a temporary faith, they clasp about him closely, and draw some sap and virtue from him; but still they are never rooted in Christ, but rooted in the old Adam; still rooted in the old covenant, were never cut off from the old root, and ingrafted into Christ, but only draw virtue from Christ to maintain their old-covenant fruit. I imagine it will be a hard chapter for some here to read, How shall I know but I am one of these that have only that faith which takes hold of Christ, like an ivy to the tree, drawing sap from him, without ever being rooted in him ? I shall offer you but one key for the opening of this difficulty, and you have need to have it opened; for it as much as your eternal salvation is worth, to mistake here. If you have no other but that temporary faith, you may believe and be damned with the devil, but cannot believe unto salvation.- Ralph Erskine, "The Pregnant Promise," in The Sermons and Other Practical Works of Ralph Erskine, pp. 237-40
The key for opening the matter, then, is this question, What know you of the difference betwixt righteousness In Christ, and righteousness From him?
Temporary faith may say, From the Lord I have righteousness and strength; but true faith says, "In the Lord have I righteousness and strength."—Temporary faith may get many things from him, but true faith gets all things in him, and is complete in him.—Temporary faith, being without root, never rooted in him, hath nothing in him, but from him; but true faith being rooted in Christ, whatever it gets from him, it rests not there, but looks to what is in him,and glories in that: "In him shall all the seed of Israel be justified, and shall glory." See Isa. xlv. 24, 25. 1 Cor. i. 30, 31. What think you the Popish way of believing unto salvation is? Indeed the refined of them go as far as some professed Protestants; they own there is no salvation but by Christ; and though they do not believe, with application, that they have any righteousness in him, yet they build upon a righteousness from Christ, saying, "It is he that gives a man power to do, and then sprinkles the man's doings with his blood, upon which he merits their life and salvation." So many such Papists amongst us, they believe that Christ only can save them, and they go to him to be saved from sin, and for grace to do better; and if they find power to do better, then- they hope they shall be saved; while yet they may be damned, and go to the devil, though they should escape all the pollutions of the world, and that even through the knowledge of Christ, not from their own strength, but from the strength and virtue of the knowledge of Christ, 2 Peter- ii. 20. But true faith comes first to Christ for righteousness, and gets a righteousness in him for justification and eternal salvation: and being rooted in Christ, grows up in him, and hath all in him; and hence can rejoice in him, even when it finds nothing but emptiness in itself; for, it is the nature of it to go out of itself to Christ in the free promise. Hence also temporary faith receives Christ conditionally, but true faith receives him freely as he is offered. Temporary believers take him for a Saviour: but, how ? even in this conditional way, if I be a servant to him, he-will be a Saviour to me; and so he serves him, and thereupon expects salvation from him: thus he bears the root, and the root bears not him. But true faith receives Christ freely for righteousness and strength both, saying, Even so I take him, both for righteousness, that he may be a Saviour to me; and for strength, that he may make me a servant to him, to serve as a son, not as a hireling. Temporary faith and legal faith believes Christ will save- me upon condition of my good behaviour for the time to come; in case I serve him, then he will save me: but gospel-faith takes Christ upon gospel-terms, as he is exhibit in the gospel promise, saying, O I dare not promise any thing to him, but I take him as promising all things to me: and, blessed be sovereign grace, that all is in the promise; for, if any thing depended upon my good behaviour and future service, I fear all would be cast loose; therefore I take a Christ for all, and a promise for all: and, O well is me, that he hath promised all, for I can promise nothing; therefore, I will rely upon the promise of salvation, 1 will rely upon the promise of sanctification. And, in this way of taking the promise freely, he comes to be furnished for a better behaviour, than all the legal and conditional believers in the world; for, as he believes the promise, so he lives upon it.