If God is omnipotent, merciful, and just, why does He permit evil to exist? The theological term "theodicy" reflects an attempt to reconcile this paradox by vindicating God's attributes of mercy and justice, in spite of the presence of evil in the world. But Christian Science solves the dilemma by disclosing the nothingness of evil—revealing that God neither creates evil nor does He permit it to exist. He knows not of it, nor does His spiritual image and likeness, man.
Evil is the outward manifestation, perceived only by the material senses, of illusory, negative mental action. In order to understand and demonstrate the allness of good and the consequent nothingness of evil, we need to be alert to the kind of mental action that we are accepting as real or entertaining within our consciousness.
Christian Science shows that if thought reflects the purity and peace of divine Mind, God, it is harmonious; and if it is not harmonious, it does not proceed from God and is therefore untrue and powerless. Mrs. Eddy writes in Science and Health "Christian Science goes to the bottom of mental action, and reveals the theodicy which indicates the rightness of all divine action, as the emanation of divine Mind, and the consequent wrongness of the opposite so-called action,—evil, occultism, necromancy, mesmerism, animal magnetism, hypnotism."
Science and Health, p. 104;
