Why is Union with Christ so Important?

Over at Green Baggins, Darryl Hart asked:

[M]aybe you can help me out here. Every time I read the law, it brings me up way short. Apparently, when you read it you feel exonerated. How DO you do it?

I answered:

Union with Christ. That is the only way to feel exonerated in the face of the law.

Darryl Hart asked:

Tfan, how can I, a sinner, be united to Christ, the righteous one? Your answer leaves me unconsoled.

I answered:

By repentance from sin and faith in His name.

Darryl Hart asked:

Tfan, where do our standards say that I am united to Christ by faith? If you look at the Westminster Confession (you know, 1646), the chapter on saving faith does not mention union.

I answered:

Our standards explain this in WLC 65-67.

Q. 65. What special benefits do the members of the invisible church enjoy by Christ?

A. The members of the invisible church by Christ enjoy union and communion with him in grace and glory.[269]

Q. 66. What is that union which the elect have with Christ?

A. The union which the elect have with Christ is the work of God’s grace,[270] whereby they are spiritually and mystically, yet really and inseparably, joined to Christ as their head and husband;[271] which is done in their effectual calling.[272]

Q. 67. What is effectual calling?

A. Effectual calling is the work of God’s almighty power and grace,[273] whereby (out of his free and special love to his elect, and from nothing in them moving him thereunto)[274] he doth, in his accepted time, invite and draw them to Jesus Christ, by his Word and Spirit;[275] savingly enlightening their minds,[276] renewing and powerfully determining their wills,[277] so as they (although in themselves dead in sin) are hereby made willing and able freely to answer his call, and to accept and embrace the grace offered and conveyed therein.[278]

See also WCF 9:

CHAPTER XI.
Of Justification.

I. Those whom God effectually calleth, he also freely justifieth: not by infusing righteousness into them, but by pardoning their sins, and by accounting and accepting their persons as righteous; not for any thing wrought in them, or done by them, but for Christ’s sake alone; not by imputing faith itself, the act of believing, or any other evangelical obedience to them, as their righteousness; but by imputing the obedience and satisfaction of Christ unto them, they receiving and resting on him and his righteousness by faith; which faith they have not of themselves, it is the gift of God.

II. Faith, thus receiving and resting on Christ and his righteousness, is the alone instrument of justification; yet is it not alone in the person justified, but is ever accompanied with all other saving graces, and is no dead faith, but worketh by love.

III. Christ, by his obedience and death, did fully discharge the debt of all those that are thus justified, and did make a proper, real, and full satisfaction of his Father’s justice in their behalf. Yet inasmuch as he was given by the Father for them, and his obedience and satisfaction accepted in their stead, and both freely, not for any thing in them, their justification is only of free grace, that both the exact justice and rich grace of God might be glorified in the justification of sinners.

IV. God did, from all eternity, decree to justify the elect; and Christ did, in the fullness of time, die for their sins and rise again for their justification; nevertheless they are not justified until the Holy Spirit doth, in due time, actually apply Christ unto them.

V. God doth continue to forgive the sins of those that are justified; and although they can never fall from the state of justification, yet they may by their sins fall under God’s Fatherly displeasure, and not have the light of his countenance restored unto them, until they humble themselves, confess their sins, beg pardon, and renew their faith and repentance.

VI. The justification of believers under the Old Testament was, in all these respect, one and the same with the justification of believers under the New Testament.

I hope that helps.

Darryl Hart asked:

Tfan told me that my hope came from being united to Christ. I asked how I a sinner could be united to a righteous God-man. Tfan, told me by faith. What I’m trying to understand is why union would be so important to Tfan’s response to me. Since most of what he quotes makes effectual calling more explicit than union, I’m still puzzled. And Jeff, I think it is curious that if union were so important (again) why does the chapter on saving faith not mention it?

I dropped the thread at that point, but now I answer, quoting Charles Hodge:

Union with Christ

The first effect of faith, according to the Scriptures, is union with Christ. We are in Him by faith. There is indeed a federal union between Christ and his people, founded on the covenant of redemption between the Father and the Son in the counsels of eternity. We are, therefore, said to be in Him before the foundation of the world. It is one of the promises of that covenant, that all whom the Father had given the Son should come to Him; that his people should be made willing in the day of his power. Christ has, therefore, been exalted to the right hand of God, to give repentance and the remission of sins. But it was also, as we learn from the Scriptures, included in the stipulations of that covenant, that his people, so far as adults are concerned, should not receive the saving benefits of that covenant until they were united to Him by a voluntary act of faith. They are “by nature the children of wrath, even as others.” (Eph. ii. 8.) They remain in this state of condemnation until they believe. Their union is consummated by faith. To be in Christ, and to believe in Christ, are, therefore, in the Scriptures convertible forms of expression. They mean substantially the same thing and, therefore, the same effects are attributed to faith as are attributed to union with Christ.
105

Justification an Effect of Faith.

The proximate effect of this union, and, consequently, the see. ond effect of faith, is justification. We are “justified by the faith of Christ.” (Gal. ii. 16.) “There is therefore now no condemnation to them which are in Christ Jesus.” (Rom. vii. 1.) “He that believeth on him is not condemned.” (John iii. 18.) Faith is the condition on which God promises in the covenant of redemption, to impute unto men the righteousness of Christ. As soon, therefore, as they believe, they cannot be condemned. They are clothed with a righteousness which answers all the demands of justice. “Who shall lay anything to the charge of God’s elect? It is God that justifieth. Who is he that condemneth? It is Christ that died, yea rather, that is risen again, who is even at the right hand of God, who also maketh intercession for us.” (Rom. viii. 33, 34.)

Participation of Christ’s Life an Effect of Faith.

The third effect of faith, or of union with Christ, is a participation of his life. Those united with Christ, the Apostle teaches (Rom. vi. 4-10), so as to be partakers of his death, are partakers also of his life. “Because I live, ye shall live also.” (John xiv. 19.) Christ dwells in our hearts by faith. (Eph. iii. 17.) Christ is in us. (Rom. viii. 10.) It is not we that live, but Christ liveth in us. (Gal. ii. 20.) Our Lord’s illustration of this vital union is derived from a vine and its branches. (John xv. 1-6.) As the life of the vine is diffused through the branches, and as they live only as connected with the vine, so the life of Christ is diffused through his people, and they are partakers of spiritual and eternal life, only in virtue of their union with Him. Another familiar illustration of this subject is derived from the human body. The members derive their life from the head, and perish if separated from it. (Eph. i. 22; 1 Cor. xii. 12-27, and often). In Ephesians iv. 15, 16, the Apostle carries out this illustration in detail. “The head, even Christ: from whom the whole body fitly joined together and compacted by that which every joint supplieth, according to the effectual working in the measure of every part, maketh increase of the body unto the edifying of itself in love.” As the principle of animal life located in the head, through the complicated yet ordered system of nerves extending to every member, diffuses life and energy through the whole body; so the Holy 106Spirit, given without measure to Christ the head of the Church, which is his body, diffuses life and strength to every member. Hence, according to Scripture, Christ’s dwelling in us is explained as the Spirit’s dwelling in us. The indwelling of the Spirit is the indwelling of Christ. If God be in you; if Christ be in you; if the Spirit be in you, — all mean the same thing. See Romans viii. 9-11.

To explain this vital and mystical union between Christ and his people as a mere union of thought and feeling, is utterly inadmissible. (1.) In the first place, it is contrary to the plain meaning of his words. No one ever speaks of Plato’s dwelling in men; of his being their life, so that without him they can do nothing; and much less, so that holiness, happiness, and eternal life depend upon that union. (2.) Such interpretation supposes that our relation to Christ is analogous to the relation of one man to another. Whereas it is a relation between men and a divine person, who has life in Himself, and gives life to as many as He wills. (3.) It ignores all that the Scriptures teach of the work of the Holy Spirit and of his dwelling in the hearts of men. (4.) It overlooks the supernatural character of Christianity, and would reduce it to a mere philosophical and ethical system.

Peace as the Fruit of Faith.

The fourth effect of faith is peace. “Being justified by faith, we have peace with God, through our Lord Jesus Christ.” (Rom. v. 1.) Peace arises from a sense of reconciliation. God promises to pardon, to receive into his favour, and finally to save all who believe the record which He has given of his Son. To believe, is therefore to believe this promise; and to appropriate this promise to ourselves is to believe that God is reconciled to us. This faith may be weak or strong. And the peace which flows from it may be tremulous and intermitting, or it may be constant and assured. (Hodge, Systematic Theology 3:16:8)

I wonder if, once Hart understands the Faith, Union, Justification, Peace connection, this kind of comment from him will cease:

In the presence of God’s law I experience great terror and dread because of its holy standard and my guilt. And yet you think I should run frolicking through the streets about God’s law?

(source)

Perhaps then he will be able to join in singing Psalm 119:

Psalm 119:97 O how love I thy law! it is my meditation all the day.

Psalm 119:165 Great peace have they which love thy law: and nothing shall offend them.

-TurretinFan

UPDATE:

Perhaps I would be remiss if I completely omitted Westminster Confession of Faith 26:1:

All saints that are united to Jesus Christ their head, by his Spirit and by faith, have fellowship with him in his graces, sufferings, death, resurrection, and glory: and, being united to one another in love, they have communion in each other's gifts and graces, and are obliged to the performance of such duties, public and private, as to conduce to their mutual good, both in the inward and outward man.