Question: Gal. 3:20: what is meant by “the mediator is not of one, but God is one”? D.
Answer: It is the principle of the law on the one hand, and of promise on the other; which the apostle contrasts, in order to deliver the Galatians or any other souls from the dangerous error of mingling them together, as unbelief is prone to do. The legal mediator is intended, Moses, not Christ; and that office implies two parties: God demanding right, and sinful man wholly unable to render it. The law therefore cannot but be for sinners a ministry of death and condemnation, as we are told in 2 Cor. 3. It is wholly different with promise; for this rests on the sole and unfailing fidelity of God Who cannot lie. As God is the only party to promise in His sovereign and unconditional grace, all He promises comes to fruition. “God is one”; whereas under law man, being under obligation to perform and failing through sin, all his hopes thus come to nothing. God on the contrary accomplishes all in and by Christ, and hence to faith. And as in Him is the Yea, so through Him also is the Amen (2 Cor. 1).