Deuteronomy 12:31-32

12:31 You must not worship the Lord your God the way they do! For everything that is abhorrent to him, everything he hates, they have done when worshiping their gods. They even burn up their sons and daughters before their gods!

Idolatry and False Prophets

12:32 (13:1) You must be careful to do everything I am commanding you. Do not add to it or subtract from it!