Why does there have to be a first cause? It seems self-evident that everything that begins to exist has a reason for its existence. This idea is called the principle of sufficient reason. Stated more fully, this principle says for everything that exists, there is a reason for its existence, either due to the causal efficacy of other beings or due to the necessity of its own nature. Is the universe a necessary thing, something that is required by its very nature? One major issue is that our modal intuitions are correct which lead us to believe that a possible world where certain features were not present could have come about. If it could have been otherwise, it is not necessary. If the universe is not necessary, then it is contingent and needs a cause for its existence.
To posit that the universe does not need a first cause is to believe that the universe is eternal. It just has always been. The problem with such a view is that Big Bang cosmology as-well-as the Bible both teach that the universe had a beginning a finite time ago. If it began some time ago, something had to have caused it. If there’s a Big Bang, there has to be some sort of Big Banger. The issue is further confounded by the fact that many believe an actual infinite to be an impossibility. Some might argue that a first cause has to exist but deny that the first cause is God himself. Why could it not be something other than God which is the first cause? Self-causation is discarded because something cannot cause itself. This would violate our normal sense experience that recognizes things do not just pop into existence. Out of nothing, nothing comes. Polytheism and the multiverse theory are to be rejected because they obviously multiple entities unnecessarily. The first cause must be beginningless for it would require a reason for itself if it possessed a beginning. From the cause’s being beginningless, it follows that such a being is changeless (in relation to the universe), immaterial (not a part of the universe), timeless (without events, time does not exist), spaceless (no spatial entity can be timeless and immaterial), and enormously powerful (all matter is owing to the being). Arguments have been marshaled also for the position that the first cause is personal. This being sounds a lot like what most people mean when they refer to God.
If everything that exists needs a cause, what about the existence of God? This is trumpeted as a salient response to the cosmological argument. Discussing three of Thomas Aquinas’ five proofs, atheist biologist Richard Dawkins ask, “All three of these arguments rely upon the idea of a regress and invoke God to terminate it. They make the entirely unwarranted assumption that God himself is immune to regress.” His logic is clear: If everything has to have a cause, does not this apply to God? No. The cosmological argument does not argue that everything must possess a cause. These arguments claim that there is something about the universe itself—either its contingency and need for explanation or its finitude in time—that requires a cause beyond itself, a cause that is self-existent and without need of a cause. Every effect has a cause. The chain of causes stops somewhere. The theist believes it stops with the uncaused Cause himself. Orthodox Christian theology has taught the independence or aseity of God is an incommunicable attribute, one he himself alone contains. The independence of God is a perfection that entails he is completely self-sufficient within himself and is not contingent upon any reality other than himself (Acts. 17:24-25; Job 41:11; Psa. 50: 10-12; Gen. 1:1; John 17:5; Psa. 90:2; Exo. 3:14). All being finds its existence in him while he is dependent on nothing. It is a quality that is more or less recognized by all humans in the very definition of “God.” This objection does not bear the force that it is thought to contain. The question of why seems to be one of the most fundamental questions of our existence finding its way to the mouths of children at a very young age. The cosmological argument is an example of that why question with a capital W.
Some have charged the theist with the fallacy of composition. The fallacy states that just because something is true about a thing’s parts does not mean that it is equally true about the sum total of the parts. But, sometimes the totality has the same characteristics as the parts on account of the parts—the universe resembles such a case. Furthermore, if the universe is a conglomeration of dependent parts, then all the parts together does not make it any less dependent. As Norman Geisler argues, “either the sum of the parts is equal to the whole or it is more than the whole. If the whole universe is equal to its parts, then the whole must be dependent just as the parts are…If…the whole universe is more than the parts and would not vanish were the parts all destroyed, then the whole universe is the equivalent of God, for it is an uncaused, independent, eternal, and necessary Being on which everything in the entire universe depends for its existence.” If everything has a reason why it exists, why is the universe a priori exempt? It appears to be an instance of special pleading. It seems that pure contingency is logically untenable, so it is difficult to believe that the universe is both contingent and uncaused. Without good cause for denying the principle of sufficient reason, this objection does not pose a significant way out of the implication of the cosmological argument.
 Douglas Groothuis,Christian Apologetics: A Comprehensive Case for Biblical Faith, 211-212.
 William Lane Craig, Reasonable Faith: Christian Truth and Apologetics, 119.
 Ibid., 116-124.
 William Lane Craig and James D. Sinclair, “The Kalam Cosmological Argument” in The Blackwell Companion to Natural Theology, William Lane Craig and J.P. Moreland. (Malden, MA.: Wiley-Blackwell, 2012), 192-194. See also Geisler, 203-207.
 Richard Dawkins, The God Delusion. (Boston, MA.: Houghton Mifflin Co., 2006), 101.
 Groothuis, 209-210.
 Wayne A. Grudem, Systematic Theology. (Grand Rapids, MI.: Zondervan, 2008), 160-163.
 Herman Bavinck, Reformed Dogmatics: Abridged in One Volume, 186-187.
 Bruce R. Reichenbach, “Is God’s Existence the Best Explanation of the Universe?” in Contemporary Debates in Philosophy of Religion, 105.
 Norman Geisler, Systematic Theology: Volume One. (Minneapolic, MN.: Bethany House, 2002), 30-31.
 William C. Davis, “Theistic Arguments” Reason for the Hope Within, Michael J. Murray. (Grand Rapids, MI.: Eerdmans, 1999), 24-25.