This fine edition brings together two of Parley P. Pratt's finest works: A Voice of Warning and Key to the Science of Theology. Key to the Science of Theology is Parley P. Pratt's all-embracing account of religion's impact on everything in day to day life. The author discusses religion, science, and the meaning of life in a passionate and concise way. A Voice of Warning is an instructing guide to the prophesies and the religious system of Mormonism which, at the time of publication, was rapidly gaining followers throughout North America. Yet foremost, it is a warning to honest Christians; by failing to heed the Biblical prophesies, believers will be unprepared to face the truths explained within the Bible, contained within the authoritative messages of the Holy Ghost. Pratt's insights into the importance of religion and the presence of the Holy Ghost in our lives has lost none of its poignant luster with the passage of time. We discover here answers to all manner of questions concerning the dizzying pace of scientific advancement, and the core spiritual principles which all good Christians - be they Mormon or otherwise - must cleave to in pursuit of a sublime life well-lived. All kinds of philosophical and religious concepts are brought to the fore by Pratt, whose learning and researches are of stunning profundity. Topics include the spiritual progress of mankind over the ages, the various attributes of the heavenly afterlife, and the origin and destiny of the universe around us. Although he wrote an ambitious work, Pratt never struggles to explain his wide-ranging points, which are delivered with genuine warmth and passion. Parley P. Pratt was an early figure in the Church of the Latter Day Saints, whose Mormon doctrines became guiding principles for many members of the church. Public spirited, he oversaw the construction of one of Utah's first roads, while also tending to spiritual matters through preaching locally and throughout a mission to Great Britain from 1839 to 1841.