A helpful commentary on Galatians 3:20

Gal 3:17 And this I say, that the covenant, that was confirmed before of God in Christ, the law, which was four hundred and thirty years after, cannot disannul, that it should make the promise of none effect.
Gal 3:18 For if the inheritance be of the law, it is no more of promise: but God gave it to Abraham by promise.
Gal 3:19 Wherefore then serveth the law? It was added because of transgressions, till the seed should come to whom the promise was made; and it was ordained by angels in the hand of a mediator.
Gal 3:20 Now a mediator is not a mediator of one, but God is one.

THE SUM:

The sense of Galatians 3:20 is that a mediator implies two opposing parties. Since the law of God was mediated, it made of God himself one of the two opposing parties, the other being Israel. Thus the Mosaic law, unlike the Abrahamic covenant, placed God in opposition to Israel, separating the two – a less than ideal situation since God seeks oneness with the believer, not separation.

THE EXPOSITION

The mediator in question, the one who mediated the law, is undoubtedly Moses, as he himself describes his work, saying: I stood between the LORD and you at that time, to shew you the word of the LORD (Deu.5:5), a mediatorial set-up which the people themselves had sought: And it came to pass, when ye heard the voice out of the midst of the darkness, (for the mountain did burn with fire,) that ye came near unto me, even all the heads of your tribes, and your elders; And ye said, Behold, the LORD our God hath shewed us his glory and his greatness, and we have heard his voice out of the midst of the fire: we have seen this day that God doth talk with man, and he liveth. Now therefore why should we die? for this great fire will consume us: if we hear the voice of the LORD our God any more, then we shall die. For who is there of all flesh, that hath heard the voice of the living God speaking out of the midst of the fire, as we have, and lived? Go thou near, and hear all that the LORD our God shall say: and speak thou unto us all that the LORD our God shall speak unto thee; and we will hear it, and do it. (Deu 5:23-27); and which God approved: And the LORD heard the voice of your words, when ye spake unto me; and the LORD said unto me, I have heard the voice of the words of this people, which they have spoken unto thee: they have well said all that they have spoken (Deu.5:28).

Indeed, the very concept of a mediator implies at least two parties that are separate in some fashion, hence: now a mediator is not a mediator of one (Gal.3:19). The form of the Mosaic revelation tended therefore in reality not only to exalt the law[1], but also to exhibit its difference from the promise made to Abraham (v.18) and the distance at which it placed men from God, especially as compared with the one-on-one intimacy wherewith God communed with Abraham (Gen.18:33). The same separation is illustrated by the vail on Moses’ face, as Paul expounds in 2Corinthians 3:13-16. The mediation of Moses was therefore a twoedged-sword, joining God and men in a covenant, and yet separating them. Indeed, the whole tabernacle set-up was one of separation: the Holy Ghost this signifying, that the way into the holiest of all was not yet made manifest, while as the first tabernacle was yet standing: (Heb.9:8); even mount Sinai itself being off-limits during God’s presence: And if so much as a beast touch the mountain, it shall be stoned, or thrust through with a dart: (Heb.12:20).

The separation between the Jews and God on Sinai was not only evidenced by the presence of a human mediator, but also by the presence of angels (Gal.3:19), by whose disposition (Acts 7:53) the law was ordained (Gal.3:19) and spoken (Heb.2:2). It is in that vein of separation and division, that Paul writes Now a mediator is not a mediator of one, but God is one (Gal.3:20). A mediator implies two separated parties, but in the law, God himself happens to be one of the two parties, and thus God is positionally separated from the other party by the law, seeing as the law required a mediator. So God is one of two, in number. But God is one can also be understood as pertaining to his essence, however, even that sense – that God is one in essence serves to highlight the division, since the oneness of God is found wholly isolated on one side of the contract, whereas the Jews find themselves on the other side of that oneness. Indeed, the purpose of the sacrifices required by the law was to make atonement (Ex.29:33, 36; 30:10; Lev.16; 17:11) for the people, the English etymology of the word being the “condition of being at one (with others)”[2]! Since the law formalized the separation between Israel and God, and since God is life (Eph.4:18, etc.), to be on the other side of that life was for Israel to be in death, hence Paul’s next thought that the law in no way could have given life (v.20). This interpretation is the simplest and thus requires the least wresting of the scriptures. It is also in line with Paul’s emphasis on oneness with God in vs.15-29. The promise is not spoken as of many, but as of one…which is Christ (v.16); but God is one (v.20); for ye are all one in Christ Jesus (v.28); and being Christ’s, then are ye Abraham’s seed (v.29); thus looping back to the promised one seed of v.16. Jesus Christ had specifically prayed the Father for our oneness in the Father and the Son: That they all may be one; as thou, Father, art in me, and I in thee, that they also may be one in us: that the world may believe that thou hast sent me (Jn.17:21). Being one with Christ is equivalent to being one with God, thus having crossed over to the other side of the divide, which was placed by the law, to enter into the oneness of God of Galatians 3:20. This oneness with God is God’s endgame, as John and Paul himself declare: And this spake he not of himself: but being high priest that year, he prophesied that Jesus should die for that nation; and not for that nation only, but that also he should gather together in one the children of God that were scattered abroad (Jn.11:51-52); and: having made known unto us the mystery of his will, according to his good pleasure which he hath purposed in himself: that in the dispensation of the fulness of times he might gather together in one all things in Christ, both which are in heaven, and which are on earth; even in him: (Eph.1:9-10); Paul therefore repeating that truth of being with God in Christ as children of God in this chapter: for ye are all the children of God by faith in Christ Jesus (Gal.3:26).

The argument that but God is one (v.20) contrasts the mediated law back to the promise made of God to Abraham without the presence of a mediator, requires too much reading into the text, besides being somewhat inaccurate, for Paul had just specified that the covenant between God and Abraham was confirmed…in Christ (v.17), so that Christ was the mediator of that covenant! One can nevertheless rightly observe that the Abrahamic covenant is greater than the Mosaic covenant, for the one was mediated in Christ (v.17) whereas the other merely by a mediator (v.19), even Moses.



The following commentaries well illustrate the excellence of the Abrahamic promise over the Mosaic law, however, those comments, while seeking to expound v.20, in fact only expound vs.17-19.

“A promise depends on one person; a mediated agreement depends on two. The weakness of the law compared to the covenant of Abraham is shown because it depends on two parties, not God alone”[3].

“God would bring man into immediate communion with Him, and not have man separated from Him by a mediator that keeps back from access, as Moses and the legal priesthood did (Exo_19:12, Exo_19:13, Exo_19:17, Exo_19:21-24; Heb_12:19-24). The law that thus interposed a mediator and conditions between man and God, was an exceptional state limited to the Jews, and parenthetically preparatory to the Gospel, God’s normal mode of dealing, as He dealt with Abraham, namely, face to face directly; by promise and grace, and not conditions; to all nations united by faith in the one seed (Eph_2:14, Eph_2:16, Eph_2:18), and not to one people to the exclusion and severance from the ONE common Father, of all other nations.”[4]

[1] David Guzik's Enduring Word Commentary

[2] Jamieson, Fausset and Brown Commentary – Galatians 3:20

[3] A truth which the Jews focus on exclusively, ignoring the great separation that the law outlined and formalized under pain of death, between them and God.

[4] atonement | Search Online Etymology Dictionary – Emphasis not in original