Christian Science explains that God is infinite Spirit, good. He is All-in-all; hence there is no other presence, power, or substance. The activity of good is all that is or can be taking place in the real spiritual universe. This is the only universe; and spiritual man, God's own image, is the only true man.
Mortality and evil spring from the supposition that matter is intelligent, real, and substantial. This inversion of reality would oppose the divine Mind, God, and His idea, man, in every particular. But matter is not substance; it is a dream, an illusion, a lie appearing real only to the carnal mind, alias the five physical senses.
Mrs. Eddy states in Science and Health: "The realm of the real is Spirit. The unlikeness of Spirit is matter, and the opposite of the real is not divine,—It is a human concept. Matter is an error of statement." On the same page she adds: "Nothing we can say or believe regarding matter is immortal, for matter is temporal and is therefore a mortal phenomenon, a human concept, sometimes beautiful, always erroneous."
Science and Health, p. 277.