The prayerful soul must be sure that "God is," and that he heeds the call of his children. The religious soul must believe in a real Divine Being. One condition necessary to successful prayer is a fixed belief in the Maker of all things. The Christian should keep his brain supplied with "axioms." An axiom is a self-evident truth, an immovable, unchangeable fact. It is a fundamental principle of which all sane men are cognizant. It is a statement of truth which is below and above all argument--a truth which all men recognize as a part of their mental existence. An axiom is simply a reference to a necessary condition in the framework of the human constitution. Every living man acts on those conditions, whether he recognizes them or not. The man whose common sense recognizes those immovable principles builds his belief and action on them safely. Prayer, like all other religious things or conditions, needs to have a sure foundation. Therefore, axioms which are used as the basis of mathematical science are true everywhere, and the worshiper needs to recognize them as fully as the civil engineer. Here are presented some of the axioms on which the believer safely rests his faith. They cannot be proven, because they are vitally and essentially true. Their nonexistence is positively unthinkable. If these axioms are not essential to all mental action, then the world is a dreamy unreality. "Two parallel lines will never run together or cross each other." All recognize the absolute truth of the statement, and yet no one ever went to the end of the lines to get local evidence of the fact. "Two halves are equal to the whole," states the college professor before his class. He would be an idiot if he tried to "prove it." He may illustrate the idea by cutting an apple into halves and putting them together again. But the essential truth of the proposition every mind had accepted before he mentioned it. "Two quantities or objects which are equal to a third quantity or object are equal to each other." A boy smiles at the waste of time in telling him such an axiomatic or self-evident fact. But the instructor is not attempting to inculcate a new principle, but rather to call attention emphatically to an immovable fact woven into the vital fabric of all human minds. The thinker who stands squarely on those fundamental facts can trust himself and can be trusted by all. A careful review of one thousand and twenty letters relating to established cases of successful prayer showed that the believer accepted as fundamentally true axiomatic facts of which the following is a partial list. We know only because the mental knowledge is an essential part of our intellectual existence. We therefore know: That two and two make four. That we exist. That we are independent, thinking beings. That there is moral obligation to do right. That there is good and evil. That our essential self is not the body.