On page 505 of the Christian Science textbook, "Science and Health with Key to the Scriptures" by Mary Baker Eddy, we read: "Understanding is the line of demarcation between the real and unreal. Spiritual understanding unfolds Mind,—Life, Truth, and Love,— and demonstrates the divine sense, giving the spiritual proof of the universe in Christian Science."
The student of Christian Science finds that spiritual understanding of God enables him to discriminate between the real and the unreal. Christ Jesus said, "God is a Spirit: and they that worship him must worship him in spirit and in truth." A greater understanding of God as Spirit develops a spiritual sense of the truth about God and His perfect creation, man and the universe, which can be progressively demonstrated here and now.
What about this false concept which claims to oppose the real? What do we find if we fall into a material misconception which seemingly binds us to the various phases of sin, sickness, and death? Through the enlightenment of the Christ Science, we recognize that this is the lie about man as material, "conceived in sin and brought forth in iniquity," and as having fallen from his high estate as God's image and likeness.