What is Christian Science?
To answer this question, you need to start with the Discoverer of Christian Science, Mary Baker Eddy (1821–1910), a lifelong student of the Bible.
After facing many physical and other challenges throughout her life, in 1866, at the age of 45, she was injured in an accident and was not expected to live. She asked for her Bible, and read an account of one of Christ Jesus' healings. As she read, she felt God's presence, and was healed.
She spent the next three years in deep study of the Bible, seeking answers to how she was healed.
She learned that God is infinite Love, completely good, and that a clear glimpse of this truth has power to heal and transform anyone. She also gained the conviction, as it says in Genesis 1:27, that "...God created man in His own image..." So in truth, man is spiritual and perfect.
This growing understanding of God and man revealed to her how Christ Jesus and his followers healed, and enabled her to heal sickness and sin through prayer and to teach others how to heal in the same way. Christian Science is based wholly on Christ Jesus' teachings and practice, and his instruction, "...He that believeth on me, the works that I do shall he do also; and greater works than these shall he do; ..." (John 14:12)
Mrs. Eddy named her discovery “Christian Science,” and in 1875 she published the Christian Science textbook, Science and Health with Key to the Scriptures. In it she described Jesus as, “...the most scientific man that ever trod the globe. He plunged beneath the material surface of things and found the spiritual cause.” (p. 313)
She defined Christian Science as, "... the law of God, the law of good, interpreting and demonstrating the divine Principle and rule of universal harmony."
(Rudimental Divine Science, Mary Baker Eddy, p. 1).