"Key to the Science of Theology" is an important book by the American writer and religious figure Parley P. Pratt, which was first published in 1855. In this work, the author explores theological themes, analyzes the basic principles of Christianity, and offers deep reflections on faith, morality, and spirituality. The book "Key to the Science of Theology" is not only a fundamental work for the study of religion, but also an extremely valuable source for anyone interested in spiritual development and searching in the middle.