The religious aspects of the question must ever have the pre-eminence in the Christian's mind, because the eternal destinies of thousands of souls are involved in this great heresy, and because Mormonism will continue to have strength and vitality as a religious system, even though it be stripped of its objectionable political and social features. The rank and file of the people are devoted to their creed. They sincerely believe themselves to be the real conservators of the faith once delivered to the Saints. They are fortified by a system of theology as plausible to the darkened understanding as it is pleasing to the natural heart. They are living under a covenant of works, upon which they have staked their all, and they have a hope of abundant rewards in the future. Their conception of the divine law is narrow and inadequate, because their notions respecting God are cramped and carnal. Gross error has become thoroughly rooted in the minds of the people. As we have already seen in treating of the political and social aspects of Mormonism, _its real power lies in its doctrines_. It is the Mormon's constant boast that nothing can shake the sure foundations of his faith. He has a sincere conviction that his doctrines are invulnerable; but, although the strength of Mormonism does lie in its doctrines, perhaps not one hundredth of the people of our land know anything about their religious tenets, save the doctrine of polygamy. Let us, therefore, endeavor to get some idea of Mormonism as a religious system--a system of doctrines and precepts; and in doing so let us consider, in the first place, I. THE SOURCES OF THEIR DOCTRINES.