Many people these days have questions about witches, so-called prophets, hypnotists, fortune-tellers, mediums, crystalball gazers, supposed miracle workers, clairvoyants, and the like. Nostradamus, Jeanne Dixon, and Edgar Cayce, who claim to foretell the future, still have significant followings. Indeed, New Age religions and non-mainstream practices are on the rise among Americans.
We can know whether anyone who claims to have "supernatural" powers really is a prophet, messenger, or servant of God. The Bible provides these instructions: "If there arises among you a prophet or a dreamer of dreams, and he gives you a sign or a wonder, and the sign or the wonder comes to pass of which he spoke to you, saying, 'Let us go after other gods which you have not known, and let us serve them,' you shall not listen to the words of that prophet or to 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 with all your soul" (Deuteronomy 13:1-3).
God further warns us, "Beloved, do not believe every spirit, but test the spirits, whether they are of God; because many false prophets have gone out into the world" (I John 4:1). This is how we should "test" the spirits: "And when they say to you, 'Seek those who are mediums and wizards, who whisper and mutter,' should not a people seek their God? Should they see the dead on behalf of the living? To the law and to the testimony! If they do not speak according to this word, it is because there is no light in them" (Isaiah 8:19-20).
This, then, is the test of a true servant of God. He will teach the people to believe and to obey exactly what the Word of God says (Deuteronomy 8:3; Matthew 4:4; Luke 4:4). The working of miracles—whether imagined or real—is not and never has been the proof of a true servant of God.