Deuteronomy 13:1-5

If there arise among you a prophet, or a dreamer of
dreams, and giveth thee a sign or a wonder,

And the sign or the wonder come to pass, whereof he
spake unto thee, saying, Let us go after other gods, which thou hast not known,
and let us serve them;

Thou shalt not hearken unto the words of that prophet,
or that dreamer of dreams: for the LORD your God proveth you, to know whether ye
love the LORD your God with all your heart and with all your
soul.

Ye shall walk after the LORD your God, and fear him,
and keep his commandments, and obey his voice, and ye shall serve him, and
cleave unto him.

And that prophet, or that dreamer of dreams, shall be
put to death; because he hath spoken to turn you away from the LORD your God,
which brought you out of the land of Egypt, and redeemed you out of the house of
bondage, to thrust thee out of the way which the LORD thy God commanded thee to
walk in. So shalt thou put the evil away from the midst of thee

Powerful Ain't it?