The Almighty God, the sell-existent, eternal, and Supreme Being, the creator and upholder of the universe, worshipped by most civilized nations. The Christian God is an infinite and absolute being; a perfect personal spirit; eternal; immutable; omniscient; omnipotent; and perfectly good, true, and righteous.

The arguments for the existence of God have been divided into the ontological, the cosmological, the psychological, the physico-teleological, and the moral.

The ontological argument starts from the idea of God itself, and demonstrates the existence of God as a necessary consequence from that idea. This form of argument was first fully developed and applied by Anselm in the 11th century. The manner in which it was stated by Anselm is this: 'God must be thought of as that being than whom none can be thought greater; but this being the highest and most perfect that we can conceive, may bethought as existing in actuality as well as in thought - that is to say, may be thought as something still greater; therefore God, or what is thought as greatest, must exist not only in thought but in fact'
This argument has been presented in other forms. Descartes, while refuting Anselm's form of the ontological argument, revived it himself in another form. Applying the test of truth which he derived from his celebrated formula - 'I think, therefore I am,' that whatever we clearly and distinctly perceive to belong to the true and unalterable nature of a thing may be predicated of it, he found on investigating God that existence belongs to his true and unalterable nature, and therefore may legitimately be predicated of him.

Another argument was adduced by Descartes to prove the existence of God, which, although not the same with the ontological argument, appears to resemble it.

It is called the psychological argument. Like the ontological argument, it starts from the idea of a supreme and perfect being, but it does not assert the objective existence of that being as implied in its idea, but infers such objective existence on the ground that we could have acquired this idea only from the being which correspond to it. The cosmological argument starts not from an idea, but from a contingent existence, and infers from it an absolutely necessary being as its cause. Stated syllogistically the argument is:

Every new thing and every change in a previously existing thing must have a cause sufficient and preexisting. The universe consists of a system of changes. Therefore the universe must have a cause exterior and anterior to itself.
The argument called the physico-teleological is that which is commonly known as the argument from design, which has been so fully illustrated by Paley in his Natural Theology. It is simply this, that in nature there are unmistakable evidences of the adaptation of means to ends, which lead us inevitably to the idea of one that planned this adaptation, that is, of God.

The moral argument is derived from the constitution and history of man and his relations to the universe, being based on such considerations as our recognition of good and evil, right and wrong, the monitions of conscience and the fact that a moral government of the world may be observed.

Another argument is based on the fact that a belief in the existence of a Supreme Being is every-where found to be implanted in the breast of man. This argument is used among others by Cicero, still it is pronounced by others to be at best only a probable argument, if it may be accepted as valid to prove anything at all.

Others argue the existence of God from the manifestations which he has made of himself to men, but these, as well as miracles, it is admitted even by Christian theists, can only be accepted as real by such as previously believed in the divine existence.