Galatians 3:20

The rendering of the first clause in our versions, Now a mediator is not a mediator of one, reduces it to an unmeaning truism. The author is not treating of mediators in the abstract, but writes of Moses the mediator of the Law that he was not mediator of one chosen family; and so contrasts God's revelation through him with the previous covenant. That covenant had been made with Abraham in person, and embraced a single chosen family (cf. Galatians 3:16) restricted from generation to generation by continuous selection of God's elect until it centred in Christ Himself. Not so the covenant of Sinai: it was addressed, not to one family (ἑνὸς, sc. σπέρματος), but to many families of Abraham's children after the flesh. This change of recipients involved a vital change in the revelation also whereas the promise had quickened faith by an appeal to gratitude and love, the Law used threats of wrath and punishment to deter corrupt and carnal natures from indulging the vices of the flesh.

The stress laid on the unity of the chosen seed in Galatians 3:16 and the ellipsis of σπέρματα with τὰ πάνατα in Galatians 3:22 justify us in understanding σπέρματος here with ἑνός. ὁ δὲ Θεὸς εἷς ἐστιν. The recurrence of the same phrase εἷς ὁ Θεός with a corresponding force in Romans 3:30 suggests its true force and connection with the context in this place. The Apostle is there urging the real harmony of God's dealings with Jews and Gentiles, however different the method employed for justifying the two severally; and argues that it is nevertheless one and the same God who will justify both. So here after differentiating the revelation made through Moses from that to Abraham, he is careful to add that the God of Sinai is one with the God of Abraham, however distinct might be the two revelations. The true force of the clause may be expressed as follows, but the God (sc. the God of Sinai) is one with the God of promise. The twofold revelation of the name of God to Moses as the God of Abraham, Isaac and Jacob, and as the eternal God I am that I am, suggests the same thought of the divine unity in spite of the various aspects in which God reveals Himself to successive generations of men.