If a prophet or a dreamer of dreams arises among you, & he gives you a   sign or a wonder today, & the sign or the wonder he spoke to you comes to pass, saying, ‘Let us go & serve other gods’ you have not known, you shall not listen to the words of that prophet or dreamer of dreams; for the Lord your God is testing you to know whether you love the Lord your God with all your heart & with all your soul…  (Deut 13:2-6 OSB)