http://www.positiveatheism.org/hist/ingersup.htm
To deny the existence of these evil spirits, to deny the existence of the Devil, is to deny the truth of the New Testament. To deny the existence of these imps of darkness is to contradict the words of Jesus Christ. If these devils do not exist, if they do not cause disease, if they do not tempt and mislead their victims, then Christ was an ignorant, superstitious man, insane, an impostor, or the New Testament is not a true record of what he said and what he pretended to do. If we give up the belief in devils, we must give up the inspiration of the Old and New Testament. We must give up the divinity of Christ. To deny the existence of evil spirits is to utterly destroy the foundation of Christianity. There is no half-way ground. Compromise is impossible. If all the accounts in the New Testament of casting out devils are false, what part of the Blessed Book is true?
As a matter of fact, the success of the Devil in the Garden of Eden made the coming of Christ a necessity, laid the foundation for the atonement, crucified the Savior and gave us the Trinity.
If the Devil does not exist, the Christian creeds all crumble, and the superstructure known as "Christianity," built by the fathers, by popes, by priests and theologians -- built with mistakes and falsehoods, with miracles and wonders, with blood and flame, with lies and legends borrowed from the savage world, becomes a shapeless ruin.
If we give up the belief in devils and evil spirits, we are compelled to say that a witch never lived. No sensible human being now believes in witchcraft. We know that it was a delusion. We now know that thousands and thousands of innocent men, women and children were tortured and burned for having been found guilty of an impossible crime, and we also know, if our minds have not been deformed by faith, that all the books in which the existence of witches is taught were written by ignorant and superstitious men. We also know that the Old Testament asserted the existence of witches. According to that Holy Book, Jehovah was a believer in witchcraft, and said to his chosen people: "Thou shalt not suffer a witch to live."
This one commandment -- this simple line -- demonstrates that Jehovah was not only not God, but that he was a poor, ignorant, superstitious savage. This one line proves beyond all possible doubt that the Old Testament was written by men, by barbarians.
John Wesley was right when he said that to give up a belief in witchcraft was to give up the Bible.
Give up the Devil, and what can you do with the Book of Job? How will you account for the lying spirits that Jehovah sent to mislead Ahab?
Ministers who admit that witchcraft is a superstition will read the story of the Witch of Endor -- will read it in a solemn, reverential voice -- with a theological voice -- and will have the impudence to say that they believe it.