My Cosmological Argument: From Cotingnecy

1. Something exists.
2. Whatever exists, does so either necessarily or contingently.
3. It is impossible that only contingent things exist.
4. Therefore, there exists at least one necessary thing.
5. If there is a necessary thing, that thing is appropriately called 'God.'
6. Therefore God exists.

(revised 8/6/'18)

This version understands Necessity and contingency largely in causal terms. The necessity that creates the universe must be understood as eternal and uncaused for two reasons: (1) The impossibility of ICR[1], there has to be a final cause or nothing would ever come to be, (2) empirically we know the universe is not eternal. See the supporting material. Atheists will often argue that this kind of argument doesn't prove that God is the necessity that causes the universe. but being necessary and creator and primary  cause makes it the sources of all things we can rationally construe that as God.

Finally, even if the cosmological argument is sound or cogent, the difficult task remains to show, as part of natural theology, that the necessary being to which the cosmological argument concludes is the God of religion, and if so, of which religion. Rowe suggests that the cosmological argument has two parts, one to establish the existence of a first cause or necessary being, the other that this necessary being is God (1975: 6). It is unclear, however, whether the second contention is an essential part of the cosmological argument. Although Aquinas was quick to make the identification between God and the first mover or first cause, such identification seems to go beyond the causal reasoning that informs the argument (although one can argue that it is consistent with the larger picture of God and his properties that Aquinas paints in his Summae). Some (Rasmussen, O’Connor, Koons) have plowed ahead in developing this stage 2 process by showing how and what properties—simplicity, unity, omnipotence, omniscience, goodness, and so on—might follow from the concept of a necessary being. It “has implications that bring it into the neighborhood of God as traditionally conceived” (O’Connor 2008: 67).[2]

There's a problem in speaking of God as "a being" since it threatens to reduce God from infinite and omnipresent to a localized entity. This is a semantic problem and we can resole it by through understanding that God is the eternal necessary aspect of being. Being is a thing and God is "that thing" which is unbounded,eternal, and necessary aspect of being. This unbounded condition is implied by the nature of cosmological necessity. The eternal causal agent that gives rise to all existing things could not be itself caused since that would just create the necessity of another explanation (it would mean that thing is not the ultimate cause but is just another contingent thing). Being eternal and necessary means the ground of being. The contrast between human finitude and the infinite evokes the senses of the numinous or mystical experience which is the basisof all religion.[3] 

Of course we understand this eternal necessary aspect of being to be God not only because the infinite evokes the numinous but also because the notion that God is being itself is a major aspect of  Christian Theology.[4]

Notes

[1] Infinite Causal Regression. For arguments against see: No Infinite Causal Regression (link)

[2] Timothy O’Connor2008, Theism and Ultimate Explanation: the Necessary Shape of Contingency, London: Wiley-Blackwell.

[3] David Steindl-Rast,OSB, "The Mystical Core of Organized religion," Greatfulness, blog, 2018

https://gratefulness.org/resource/dsr-mystical-core-religion/

[4] Timothy Ware, The Orthodox Church NY: Penguin,1964.65