The carnal, or mortal, mind is basically lazy. It is the belief of life in matter, and in this belief whatever requires effort is tiring. In its suggestions to us that mortal mind is our mind and that matter and its conditions constitute our life, mortal mind rationalizes. It suggests that we can demonstrate divine Truth without making the effort to learn the system which has been given us for attaining the truth.
Specifically, mortal mind suggests that it does not matter how one states the truth or how well one understands the statement of truth; it only matters how much of the spirit one expresses. But in "Science and Health with Key to the Scriptures," page 495, Mrs. Eddy presents the question, "How can I progress most rapidly in the understanding of Christian Science?"She begins her answer in these words: "Study thoroughly the letter and imbibe the spirit."
One who expects to use the truths of Christian Science to heal diseases and discords must recognize the way in which Christian Science has come to us. It was revealed by Mrs. Eddy, a follower of Christ Jesus. Jesus taught and demonstrated the spiritual truths of Christian Science, but he did not explain the method for attaining and demonstrating these truths. He promised that there would be another Comforter, who, he said, would "teach you all things" (John 14:26).