The Law and God’s Promise (Galatians 3:15-25)NLT

15  Dear brothers and sisters, here’s an example from everyday life. Just as no one can set aside or amend an irrevocable agreement, so it is in this case. 

16  God gave the promises to Abraham and his child. And notice that the Scripture doesn’t say “to his children,” as if it meant many descendants. Rather, it says “to his child”—and that, of course, means Christ.
17  This is what I am trying to say: The agreement God made with Abraham could not be canceled 430 years later when God gave the law to Moses. God would be breaking his promise. 

18  For if the inheritance could be received by keeping the law, then it would not be the result of accepting God’s promise. But God graciously gave it to Abraham as a promise.

19  Why, then, was the law given? It was given alongside the promise to show people their sins. But the law was designed to last only until the coming of the child who was promised. God gave his law through angels to Moses, who was the mediator between God and the people.
20  Now a mediator is helpful if more than one party must reach an agreement. But God, who is one, did not use a mediator when he gave his promise to Abraham.
21  Is there a conflict, then, between God’s law and God’s promises? Absolutely not! If the law could give us new life, we could be made right with God by obeying it.
22  But the Scriptures declare that we are all prisoners of sin, so we receive God’s promise of freedom only by believing in Jesus Christ.
23  Before the way of faith in Christ was available to us, we were placed under guard by the law. We were kept in protective custody, so to speak, until the way of faith was revealed.
24  Let me put it another way. The law was our guardian until Christ came; it protected us until we could be made right with God through faith.
25  And now that the way of faith has come, we no longer need the law as our guardian.