Galatians 3:24-26 So then, the law was our guardian until Christ came, in order that we might be justified by faith. (25) But now that faith has come, we are no longer under a guardian, (26) for in Christ Jesus you are all sons of God, through faith.
The law was a guardian. In verse 24 Paul gives the expiration date for this guardian and that is when Christ came. With the incarnation of Christ, the guardian was replaced with faith. Since the guardian and the law are the same thing, this means the law was replaced by faith in Christ. The Ten Commandments as a unit is a part of the law and was the covenant contract for the Mosaic covenant. Christ Jesus perfectly met the conditional legal requirements of this covenant contract for all that are in Christ through faith. Therefore, the entire law has become obsolete by faith in Christ and not just arbitrary unbiblical categories of the law. However, the precepts of nine of the Ten Commandments are still valid, since they have been repeated, and Jesus has strengthened two of them in the New Testament. Believers are free from the Ten Commandments as a covenant contract, but are not free from the precepts as restated in the New Testament.
Focus on Christ #89