A Christian Science demonstration is a practical proof in one's experience that the teachings of this Science are true.
Christian Science reveals a perfect creator and a perfect creation. It teaches that because God is infinite Spirit, life and the universe are really spiritual. Matter, the opposite of Spirit, is an illusion of the physical senses, a subjective condition of material thinking. In the universe of Spirit, matter has no place.
Similarly, evil can have no place in true, spiritual, perfect existence, which is the expression of God, who is Love, or good. Hence the demand of Jesus: "Be ye therefore perfect, even as your Father which is in heaven is perfect." Matt. 5:48;