(Galatians 3:23-29 ESV)
 Now before faith came, we were held captive under the law, imprisoned until the coming faith would be revealed.  So then, the law was our guardian until Christ came, in order that we might be justified by faith.  But now that faith has come, we are no longer under a guardian,  for in Christ Jesus you are all sons of God, through faith.  For as many of you as were baptized into Christ have put on Christ.  There is neither Jew nor Greek, there is neither slave nor free, there is no male and female, for you are all one in Christ Jesus.  And if you are Christ's, then you are Abraham's offspring, heirs according to promise.
Part 2: Verse 24-25 – The guardian.The law [Mosaic Covenant] was a temporary guardian that came 430 years after the covenant of promise was given to Abraham and ended with the coming of Christ. Paul explains that Jews were no longer under the law; therefore, it was not a permanent covenant. By fulfilling the law [Mosaic Covenant] Jesus made justification by faith a reality for all who believe. Jesus instituted a New Covenant, which made the Mosaic “law” Covenant obsolete [Hebrews 8:13]. The law saved no one and even those saved under the dispensation of the Mosaic Covenant were saved by faith in a coming redeemer. The New Covenant is completely new and not like the Mosaic Covenant that it replaced [Hebrews 8:7].