The Old Testament

The Old Testament is not contrary to the New: in both, everlasting life is offered to mankind by Christ. The ceremonial law of Moses does not bind Christians, nor are the civil precepts of necessity to be received in any commonwealth — yet no Christian is free from the obedience of the commandments which are called moral.

Don't think that I came to destroy the law or the prophets. I didn't come to destroy, but to fulfill.
— Matthew 5:17 (WEB)

Note

The classic Christian distinction between moral law (binding), ceremonial law (fulfilled in Christ), and civil law (instructive but not normative).

Bible references

Matthew 5:17-18 · Romans 3:21-22 · Romans 7:7-12 · Hebrews 8:6-13 · Galatians 3:23-25 · Romans 13:8-10