The Power of a Promise
15 Brethren, I speak in terms of human relations: even though it is only a man’s covenant, yet when it has been ratified, no one sets it aside or adds conditions to it. 16 Now the promises were spoken to Abraham and to his seed. He does not say, “And to seeds,” as referring to many, but rather to one, “And to your seed,” that is, Christ. 17 What I am saying is this: the Law, which came four hundred and thirty years later, does not invalidate a covenant previously ratified by God, so as to nullify the promise. 18 For if the inheritance is based on law, it is no longer based on a promise; but God has granted it to Abraham by means of a promise.
19 Why the Law then? It was added because of transgressions, having been ordained through angels by the agency of a mediator, until the seed would come to whom the promise had been made. 20 Now a mediator is not for one party only; whereas God is only one. 21 Is the Law then contrary to the promises of God? May it never be! For if a law had been given which was able to impart life, then righteousness would indeed have been based on law. 22 But the Scripture has shut up everyone under sin, so that the promise by faith in Jesus Christ might be given to those who believe.
The apostle Paul warns the Galatians that they are basing their salvation on their personal obedience to the law of Moses instead of on the promises God made in His covenant with Abraham. They were elevating God’s secondary and temporary commandments to Moses above God’s primary and permanent promises to Abraham. To correct the Galatians, Paul offers an example to illustrate his main point before asking and answering two questions about the law.