The Catechism in Questions & Answers

272. What is the purpose of the Mosaic Law?

The Mosaic Law provides instruction for God-pleasing conduct. It is a help in life given by God, which shows the way to goodness and helps avoid evil.

“He has shown you, O man, what is good; and what does the Lord require of you but to do justly, to love mercy, and to walk humbly with your God?”
Micah 6: 8