Q. 39 What is the duty which God requireth of man?A. The duty which God requireth of man is obedience to His revealed will.Three things to note about our duty: It is a duty that is required. Both the Catechism and our passage in Micah say it is required. This ought to be obvious to you, but too often it is not. You are sorely mistaken if you think serving God is just a matter of personal preference.

WSC Q40: The Origin of the Moral Law

The idea of imparting a body of truth (rudiments of the faith) is found repeatedly in scripture under many different terms and descriptions. We are not given a complete catechism or confession in the Bible. That is because we are to write our own according to the needs of the day. They must refute new heresies as they arise. Our Lord has called us to catechise in His church… to teach disciples the basics of the faith. Make the most of this instruction: memorise your Catechism, listen to the messages, and pray for the Spirit to work.