Deuteronomy 13:1-3

1“If a prophet arises among you, or a dreamer of dreams, and gives you a sign or a wonder,

2and the sign or the wonder which he spoke (foretold) to you comes to pass, and if he says, ‘Let us follow after other gods (whom you have not known) and let us serve and worship them,’

3you shall not listen to the words of that prophet or that dreamer of dreams; for the Lord your God is testing you to know whether you love the Lord your God with all your heart and mind and all your soul [your entire being].