18 For if the inheritance is of the law, it is no longer of promise; but God gave it to Abraham by promise.
19 For what then serves the law? It was added because of rebellions until the seed should come to whom the promise was made, and it was ordained by angels in the hand of a mediator.
20 Now a mediator is not a mediator of one, but God is one.
21 Is the law then against the promises of God? No, in no wise, for if there had been a law given which could have given life, verily righteousness should have been by the law.
22 But the scripture has concluded all under sin that the promise by faith of Jesus Christ might be given to the believers.
23 But before faith came, we were under the law, shut up unto the faith which should afterwards be revealed.
24 Therefore the law was our schoolmaster to bring us unto Christ, that we might be justified by faith.