Galatians 3:17-19

Twentieth_Century(i) 17 My point is this--An agreement already confirmed by God cannot be canceled by the Law, which came four hundred and thirty years later, so as to cause the promise to be set aside. 18 If our heritage is the result of Law, then it has ceased to be the result of a promise. Yet God conferred it on Abraham by a promise. 19 What, then, you ask, was the use of the Law? It was a later addition, to make men conscious of their wrong-doings, and intended to last only till the coming of that 'offspring' to whom the promise had been made; and it was delivered through angels by a mediator.