Atheists have often argued that God is not a plausible explanation for the universe. What they mean by that is that we don't know enough about God to judge the value of the explanation, and that issues such as the complexity problem prevent a clear understanding. The plausible explanation thing is not a very good standard by which to judge the efficacy of belief. The reason for religions is not a scientific motivation to explain the workings of the physical world. The reason religion exists is becuase we have an empirical sense of the numinous, a sense referred to as "the religious a priori." Religion is not intended as an explanation in the sense that scinece is. It's not meant to be a means of explaining the workings of the physical world. That kind of thinking went out with the nineteenth century.
The concept of God is that of the foundation of reality. There is no basis for a standard of plausibility in dealing with foundations of reality since we have no other examples of foundational reality to compare to. This observation in a nutshell beats all of their arguments about plausibility, because it says that plausibility is the wrong standard by which to judge the efficacy of belief. This observation leads to a realization that actually destroys most of the arguments made about God an probability and standard of scinece.
Science has to have two things: predictive power and falsifiability. That's in addition to replicator and representative sample and double all the together things all of those are made impossible if you don't have these two. Science can't prove it can only disprove. if there is no disproof it's not assumed proven it's assumed a match with theory then theory is assumed to be verisimilitude. Science is not the acquisition of truth its' verisimilitude.
Since God is synonymous with truth (according to the primordial assertion of belief--that's the foundational assumption made in belief--the religious a prori) God is not subject to falsification. God is not subject to predictability God is not a matter of empiricism becuase God is not a thing in creation. This idea that God is synonymous with turth is met with consternation by atheists, and one can understand why. One might think this is becuase since the atheist is dedicated to rejecting believe he/she can't very well accept a religious a priori that puts God in at the foundational level. Yet, there's a more basic reason than that why this idea is upsetting them. It's because it is predicated upon a different notion of truth than any that they understand or have been taught to think about. The typical atheist notion of truth is pretty much one of verisimilitude. It's surface level, it excludes any sort of depth of being. Things are not any more than they seem. There's no underlying issue with being it's just a surface matter of does X exist or not?
The notion of truth with which St. Augustine understood God's synonymy is a kin to the concept dreaded by Postmoderns, the "meta narrative." We are talking about Truth with a capital "T." In bold letters yet. This notion of truth is the overarching explanation for all of reality, depth and all, not just the surface explanation of the existence of a given X. This kind of truth is apt to be rejected by atheists because it hints at not only God but notions such as sin and judgment and virtue and the whole metaphysical nine yards. This is not only installing God at the epistemological and metaphysical level, without a fight so to speak, but it also excludes the replacement religion atheism turns to for substitution in the face of losing the advantages of God belief. In other words, one can't work the doings of science upon the epistemic foundation of reality becuase it's at a higher epistemological level than anything in science: it's not a matter of inductive abstraction.
Belief in God can be warranted or unwarranted, not proved or disproved.
Augustine never made an argument for the existence of God because for him God was known with certainty and immediacy. God is immediately discerned in the apprehension of truth, thus need not be “proved.” God is the basis of all truth, and therefore, cannot be the object of questioning about truth, since God is he medium through which other truths can be known. Tillich said:
Augustine, after he had experienced all the implications of ancient skepticism, gave a classical answer to the problem of the two absolutes: they coincide in the nature of truth. Veritas is presupposed in ever philosophical argument; and veritas is God. You cannot deny truth as such because you could do it only in the name of truth, thus establishing truth. And if you establish truth you affirm God. “Where I have found the truth there I have found my God, the truth itself,” Augustine says. The question of the two Ultimates is solved in such a way that the religious Ultimate is presupposed in every philosophical question, including the question of God. God is the presupposition of the question of God. This is the ontological solution of the problem of the philosophy of religion. God can never be reached if he is the object of a question and not its basis.
Augustine says God is truth. He doesn’t so much say God is being as he says God is truth. But to say this in this way is actually in line with the general theme we have been discussing, the one I call “super-essential Godhead,” or Tillich’s existential ontology. Augustine puts the emphasis upon God’s name as love, not being. Since he was a neo Platonist he thought of true reality as beyond being and thus he thought of God as “beyond being.” This makes no sense in a modern setting since for us “to be” is reality, and to not be part of being would meaning being unreal. But in the platonic context, true reality was beyond this level of reality and what we think of as “our reality” or “our world” is only a plane reflection of the true reality. We are creatures of a refection in a mud puddle and the thing reflected that is totally removed from our being is the true reality. It was this distinction Tillich tried to preserve by distinguishing between being and existence.
Augustine looked to the same passage in Exodus that Gilson quotes in connection with Aquinas. Augustine’s conclusions are much the same about that phrase “I am that I am.” This is one of his key reasons for his identification between God and truth. He saw the nature of God’s timeless being as a key also to identifying God with truth. The link between God and truth is the Platonic “one.” Augustine puts the forms in the mind of God, so God becomes the forms really. The basis of this identification is based partly upon God’s eternal nature. From that point on it’s all an easy identification between eternal verities, such as truth, eternal being, beauty, the one, and God. The other half of the equation is God’s revelation of himself as eternal and necessary through the phrase, for very similar reasons to those listed already by Gilson, between I am that I am and being itself (or in Augustine’s case the transcended of being). “He answers, disclosing himself to creature as Creator, as God to man, as Immortal to mortal, eternal to a thing of time he answers ‘I am who I am.’”
 Donald Keef, Thomism and the Ontological Theology: A Comparison of Systems. Leiden, Netherlands: E.J. Brill, 1971, 140.
The “two Ultimates” discussed are philosophy and Religion.
 Paul Tillich, Theology of Culture, 12-13
 The quotation above from the Levenson and Westphal book says Augistine believe God was being itself, Marion seems to say that Augustine put God beyond being. I think it’s debatable as to which he did because he didn’t say directly which it was. I’m assuming Marion is probably right just because of the time in which he lived and because he was a Platonic thinker.