Jane: John, are you familiar with Carl R. Kordig’s deontic argument for God’s existence?
John: No. I am not. Would you be kind to explain it to me?
Jane: Kordig argued that a deontically perfect being ought to exist. If deontically perfect being ought to exist, then such being can exist. A deontically perfect being cannot be a contingent being. Therefore, a deontically perfect being must exist.
John: What justification does Kordig offer to believe that a deontically perfect being ought to exist?
Jane: He believes that even though an individual may hold that God does not exist, that individual should grant that most perfect being ought to exist.
John: Well! I am not persuaded by that. Argumenti causa, say I grant that, how can a person possibly defend the idea that God, a deontically perfect being, cannot be a contingent being?
Jane: Kordig would argue that the idea of contingent God is metaphysically impossible. It is like the idea of a square that is also a circle at the same time and same sense. It is simply a logical contradiction.
John: How is contingent God a logical contradiction?
Jane: Because deontically perfect being, per definition, must possess maximal excellence in existence. Kordig assumed that, everything else being equal, necessary existence is better than contingent existence.
John: But existence is not a predicate, Jane, following Immanuel Kant.
Jane: Kordig could grant Kant’s proposal. He would argue that though existence is not a predicate necessary existence surely is.
John: Mh! I see. I do not find his argument persuasive though.
Jane: Neither do I, John. Although such arguments do not persuade us, they do offer rational justification for why theists do believe in God.
* Kordig, C. R. (1981) ‘ A Deontic Argument for God’s Existence,’ Noús Vol. 15, No. 2:207-208
With All I Am 
Either a deontically perfect being exists or deontics is empty.Worse, if the truths of deontics are multiply realizable there are innumerable such beings. Most are smelly old child molesters. Once we grasp that deontics must get us to admit we are utterly stupid, we realize that ‘smelly old child molester’ is a rigid designator of ‘deontically perfect being’ because, you see, ‘smelly’ and ‘old’ and ‘child molester’ are wholly contingent terms and thus have no descriptive force.
Schopenhauer argued, and I think I agree with him, that everything that exists is both necessary and contingent. He argues it is necessary with respect to its cause and contingent in respect to everything else. He concludes nothing is absolutely continent or necessary.
We know God exists because of his perpetual and completely life-transforming self-revelations, as the “Spirit”–completely independent of the flesh and of deontology.