In Science and Health with Key to the Scriptures, Mary Baker Eddy notes the many examples in the Bible of Christ Jesus casting out sin and sickness, and overcoming death. She shows that he was able to do this by understanding them as material illusions contrary to God and God’s spiritual creation. Jesus said, “Ye shall know the truth, and the truth shall make you free” (John 8:32). 

One day a number of years ago, I had an opportunity to put this spiritual understanding into practice. As I got up from the table after finishing a meal, my left leg was suddenly too painful to put my weight on. I limped a couple of steps and then stopped. It came to me from my understanding of Christian Science—the spiritual laws by which Christ Jesus healed—that there was no divine cause for this condition; therefore, I had to classify it as he surely would have: as unreal—as, for example, he did when he raised Jairus’ daughter from death (see Mark 5:22–24, 35–42). 

I understood that God is ever present and the only creator and only ever causes good for His children, including me. Since this painful condition was obviously not good, I knew it couldn’t be true. I decided to put my foot down firmly on the ground and walk normally. The pain and weakness disappeared almost immediately. However, every time I got up from a sitting position that day, my leg became painful again, so I repeated my affirmation of what is true of God and man and followed it with the same action. Each time, the problem quickly disappeared.