Deuteronomy 8:19

8:19 Now if you forget the Lord your God at all and follow other gods, worshiping and prostrating yourselves before them, I testify to you today that you will surely be annihilated.

Deuteronomy 12:31

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!