Norman Geisler on Evil

Evil is not something that has an existence all its own; rather, it is a corruption of that which already exists. 

Evil is the absence or privation of something good. 

Rot, for example, can exist only as long as the tree exists. Tooth decay can exist only as long as the tooth exists. 

Rust on a car and a decaying carcass illustrate the same point. Evil exists as a corruption of something good; it is a privation and does not have essence by itself. 

Norman Geisler tells us, “Evil is like a wound in an arm or moth-holes in a garment. It exists only in another but not in itself.”