This fine printing brings together two of Parley P. Pratt's excellent 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. Parley P. Pratt was an early figure in the Church of the Latter Day Saints, whose Mormon doctrines became guiding principles for members of the church.