Galatians 3:19 (KJV)

That the blessing of Abraham might come on the Gentiles through Jesus Christ; that we might receive the promise of the Spirit through faith.

Brethren, I speak after the manner of men; Though it be but a man's covenant, yet if it be confirmed, no man disannulleth, or addeth thereto.

Now to Abraham and his seed were the promises made. He saith not, And to seeds, as of many; but as of one, And to thy seed, which is Christ.

And this I say, that the covenant, that was confirmed before of God in Christ, the law, which was four hundred and thirty years after, cannot disannul, that it should make the promise of none effect.

For if the inheritance be of the law, it is no more of promise: but God gave it to Abraham by promise.

Now a mediator is not a mediator of one, but God is one.

Is the law then against the promises of God? God forbid: for if there had been a law given which could have given life, verily righteousness should have been by the law.

But the scripture hath concluded all under sin, that the promise by faith of Jesus Christ might be given to them that believe.

But before faith came, we were kept under the law, shut up unto the faith which should afterwards be revealed.

Wherefore the law was our schoolmaster to bring us unto Christ, that we might be justified by faith.