Author and theologian Orson Spencer was a prominent early intellectual of the Church of the Latter-Day Saints: in this book, he explains the spiritual tenets of Mormonism in a series of fifteen letters.

We find here a spirited effort by Orson Spencer to detail the theology of Mormonism for the reader, with reference to the most prominent figures within the denomination. He felt moved to author letters concerning such tenets as water baptism, the true and ineffable nature of God, and the latter-day judgements in order for the general public to understand Mormon beliefs.

Spencer originally sought to enter the Christian ministry as a Baptist, but was taken by the faith of the fledgling Mormon movement. With the encouragement of his brother, he was baptized into the denomination in 1841, and in short order became distinguished for his theological knowledge.

He led one of the pioneer companies who made the journey from the Eastern seaboard to Salt Lake City, Utah. Later he undertook missionary work in Europe and the Cherokee nation - it was during his journey to Cherokee lands that he contracted malaria which tragically would prove deadly; Spencer succumbed to the illness at the age of fifty-three.