Q. 88 What are the outward means whereby Christ communicateth to us the benefits of redemption? A. The outward and ordinary means whereby Christ communicateth to us the benefits of redemption are His ordinances, especially the word, sacraments, and prayer; all which are made effectual to the elect for salvation. He Himself uses these means to bring the benefits of His redemption to us.

WSC Q89: How God Uses the Bible in Our Lives

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.