Now a mediator is not a mediator of one, but God is one.
All Commentaries on Galatians 3:20 Go To Galatians 3
Cornelius a Lapide
AD 1637
Now a mediator is not a mediator of one, but of two, in this case of two peoples, Jews and Gentiles, to whom Christ acts as mediator, says Ambrose. (2.) Or, Christ is not a mediator of one nature, but of two, the Divine and the human. (3.) Or, Moses is not a mediator of one will and purpose, because as a man he was subject to change. God on the contrary is unchangeable in His will and promise. Adam leans to this explanation. But all these are beside the phraseology of Scripture and the drift of the Apostle.
(4.) A better interpretation is that Christ is a mediator not of one but of two—not of two Gods, as though Father and Son make two, according to the heresy of Arius and Nestorius—not between God and angels, for the good angels need no mediator, and the evil angels cannot derive any benefit from one—but He is a mediator between the two parties, God on one side and man on the other. And the inference drawn is that it is not the law, but Christ, that redeems us and reconciles us to God. This explanation is supported by Augustine, Theophylact, Anselm.
(5.) The best interpretation of the clause is that the Apostle is explaining the character of a mediator. The mediator Moses, he seems to say, is not of one but of two determinate parties, viz, God and the Hebrews , but not of God and Christians. On the other hand, God is One, not two. The Apostle is not building his argument on these words, except indirectly, but is merely contrasting the dual character of a mediator with the unity of God. It is on this latter fact that he relies to prove his case.
But God is one. There are not two Gods, one of whom is the God of the law and of the Jews, the other of Abraham and of Christians, as the Manichæans have thought, but the God of Jews and of Christians is one and the same—the law and the Gospel proceed from the same Author. Accordingly, it being the same God, He could not intend that the law should annul His promise to Abraham of giving His righteousness to all nations in Abraham"s seed, i.e, in Christ, or, in other words, through faith in Him; else would He be inconstant, the very thought of which is impious. Rather He gave the law to be our pedagogue to Christ. It Isaiah , therefore one and the same God who made Moses the mediator between Himself and the Hebrews; and, when he was superseded, between Himself and Christians of all nations, and so fulfilled His promise to Abraham, that He would give through Christ the blessing of justification to all nations.
This interpretation is confirmed by the parallel passage in 1 Timothy 2:5, where, from the fact that the same God is God of all nations, the Apostle proves that He wishes all men to be saved, and from the same principle he infers that there is one mediator between God and men, the man Christ Jesus. God, he argues, does not wish for the salvation of the Jews only, but of all nations. Again, not only the Jews, but all nations have fallen into sin, and stand in need of a redeemer. This cannot be Moses, for he was mediator to the Jews only; therefore it must be Christ. Moses, therefore, must give way to Him, as the seed promised to Abraham, in whom all nations should be blessed. So Gennadius in Å’cumenius, and, following him, Salmeron.
