A Cumulative Case for the Existence of God

by Brian Auten

The Ultimate Question

Does God exist? This is arguably the most important question that one will ever ask. The answer to this question will change how one views reality, morality, ethics, values, and life’s decisions. The existence of God determines how one sees life and interprets reality. The answer has eternal ramifications. American philosopher and author Mortimer Adler said, “More consequences for thought and action follow the affirmation or denial of God than from answering any other basic question.”[1]

For these same reasons, some would avoid the question altogether. However, it would seem wise for the uncertain or skeptical person to invest themselves seriously in finding the answer. As Blaise Pascal, the French philosopher, mathematician and physicist, wrote, “…there are only two classes of persons who can be called reasonable: those who serve God with all their heart because they know him, and those who seek him with all their heart because they do not know him.”[2]

Proof and Evidence

God cannot be proven to exist in the same way one could prove the existence of an automobile or a teapot. By his very nature, God is not substantive, tangible or physically observable. So when one asks for physical proof for the existence of God, it could be compared to asking for physical proof for a mind. In that case, absolute proof is unreasonable, but the belief is rational because the evidence is abundant. Moreover, alternative explanations for the evidence of a mind would seem absurd when compared with the simple conclusion that a mind exists.

With the nature of proof and evidence in view, a cumulative case for the existence of God can be made.[3] A cumulative case is one that does not consist of a single or decisive argument, but rather tries to show that God’s existence makes more sense than any alternative hypothesis in light of all the available evidence.[4]

Sufficient Reason

German philosopher and mathematician Gottfried Leibniz asked the question, “Why is there something rather than nothing?” Why does anything at all exist? There must be an answer to this question because, “nothing happens without a sufficient reason.”[5] He pointed out that for everything there must be a sufficient reason.

This basic principle can be observed from the smallest material things to the largest. There must be a sufficient reason or explanation for any state of affairs. It follows that the existence of the universe itself must have a sufficient reason. Leibniz argued that the reason for the universe must be found outside the universe, in a being whose sufficient reason is self-contained.[6]

From the principle of sufficient reason, it can be demonstrated that the existence of God is logical and metaphysically necessary.

Order, Information, and Design

English theologian and philosopher William Paley asserted that every watch requires a watchmaker.[7] He describes how someone would respond who, having never seen a watch before, happened to discover one in nature. That person would observe the watch’s intricacy, precision, complexity, and apparent purpose. He would by no means assume the watch “just happened.” Rather, he would rightly infer a watchmaker from the observable evidence of design in the watch. The watch requires a watchmaker. Paley then goes on to describe that creation itself points to a Creator.

Consider the order and complexity contained in DNA, the nucleic acid that contains the genetic instructions used in the development and functioning of all living organisms. As leading atheistic evolutionist Richard Dawkins admits, “There is enough information capacity in a single human cell to store the Encyclopedia Britannica, all 30 volumes of it, three or four times over.”[8] This set of instructions is extremely complex, intricate, and orderly. It is considered the blueprint for all living things. It contains the design and operating instructions for life. Human DNA contains billions of “letters,” all in a specific order, all for a specific purpose. The inference of a designer from such a combination of order, information, and design is profoundly amplified when one considers the myriad forms of life on the planet.

Aside from the apparent design of life, consider the order and fine-tuning of the universe itself. There are certain specific, necessary conditions that must be in place for life to exist on earth. These constants include such things as oxygen level, atmospheric transparency, moon-earth gravitational interaction, carbon dioxide level, and gravity. If any one of these constants were adjusted even by the smallest fraction of a percent, it would render life on earth impossible.[9] Astrophysicist Hugh Ross has revealed over 122 of these constants.[10] Theoretical physicist Paul Davies said:

It is hard to resist the impression that the present structure of the universe, apparently so sensitive to minor alterations in the numbers, has been rather carefully thought out . . . the seemingly miraculous concurrence of [these] numerical values must remain the most compelling evidence for cosmic design.[11]

When one looks at the order, information, and design in nature and the cosmos, there are two options: it came about by random chance without reason, or it was created by an intelligent designer. The evidence seems to cry out for a designer.

The Beginning of the Universe

Modern cosmology has shattered the old idea that the universe is eternal; that is, that the universe had no beginning. Science has shown that the universe has not been around forever—space, time and everything that exists had a definite beginning. This can be demonstrated by such things as the second law of thermodynamics, the expansion of the universe, and cosmic background radiation.[12] Commenting on the evidence for a definitive beginning of the universe, physicist and cosmologist Robert Jastrow states:

Now we see how the astronomical evidence leads to a biblical view of the origin of the world. The details differ, but the essential elements in the astronomical and biblical accounts of Genesis are the same: the chain of events leading to man commenced suddenly and sharply at a definite moment in time, in a flash of light and energy.[13]

This leads a very powerful argument for the existence of God called the kalam cosmological argument. The argument is as follows: 1) whatever began to exist must have a cause, 2) the universe began to exist, 3) therefore, the universe had a cause.[14] This argument is based upon the law of causality and the scientific evidence of the beginning of the universe. Because every event has a cause, the beginning of the universe requires a cause. The beginning could not be from nothing, because nothing comes from nothing. Something cannot bring itself into existence. There must be a higher, external, cause beyond the universe. By nature, God is eternal and uncaused; he is the cause that the universe requires to reconcile the evidence of a beginning.

St. Thomas Aquinas, the most famous medieval philosopher-theologian, made a similar argument from the principle of causality. Based on the principle of motion, Aquinas argued that there must be an “unmoved mover,” or a first cause of all motion, and this is God. For example, a watch could not run without a spring even if it had an infinite number of gears; a train could not move without an engine even if it had an infinite number of cars.[15] Since something cannot cause itself, Aquinas points to God as the First Cause and the Unmoved Mover of all things.

Atheist Quentin Smith refused to accept such a conclusion and opted for another view: “the most reasonable belief is that we came from nothing, by nothing, and for nothing.”[16] One questions the rationality of such a conclusion. Because the universe is not eternal, had a beginning, and could not have caused itself, the most plausible explanation is the existence of God as Creator of the universe.

Universal Truths

The existence of God makes sense of universal truths. If something is true, it is true for all people, in all places, at all times. Truth is not dependent upon someone’s knowledge of it. Truth corresponds with reality.[17] A couple of examples are mathematics and the laws of logic. No one invented mathematics or logic. They exist independently and correspond with reality. They are universal, unseen, and true.

In an atheistic worldview, everything came from nothing, by nothing, and for nothing—there is no foundation for universal truths. Yet they are undeniable. In order to even argue against the laws of logic, one must use the laws of logic. Universal truths exist regardless of one’s belief.

Such truths are not the product of nature, material or the human mind, yet there must be an ultimate source for them. The existence of God is the most plausible explanation for universal, unchanging truths because only God can account for their existence.


Every person has a moral compass that they live by. This is commonly known as the conscience. The word conscience means “with knowledge.” This has also been called the moral law. One who would deny the existence of the moral law would soon admit differently if he himself were the recipient of a morally wrong action. Norman Geisler put it rightly: “the moral law is not always the standard by which we treat others, but it is nearly always the standard by which we expect others to treat us. It does not describe how we actually behave, but rather it prescribes how we ought to behave.”[18]

Man himself does not account for this moral law, for it is a prescriptive principle that is above man, which sits in judgment on him. If there were no transcendent moral law, society could not call the atrocities of the holocaust morally wrong. If there were no standard for right and wrong, the torture of innocent babies for fun would not be appalling, but simply “different.” Certain actions are always wrong, for all people, at all times. Because there is a Moral Law, there must be a Moral Lawgiver. It is God who accounts for fairness, right and wrong, justice, morality, ethics, and conscience. Without God, there would be no absolute morals. Hence, we have evidence for the existence of God because of the moral law.

The Absurdity of Life Without God

There are two options. God exists, or God does not exist. A non-theistic worldview is severely lacking in its account for the existence of the universe, the beginning of the universe, and the design of the universe. Here, the atheistic worldview relies on long periods of time and random chance to produce something from nothing, order from chaos, life from non-life, and intelligent minds from mere matter. The atheist worldview has no ultimate foundation for morality. Atheism leaves man hopeless, helpless, and meaningless. If atheism is true, then man has no inherent dignity or purpose. All is random, temporal, and empty.


Absolute proof is not required to believe in God. A rational person can have a reasonable faith that is based upon good evidence. However, many reject God not for intellectual reasons, but for emotional reasons. The implications of God’s existence seem too uncomfortable for some; He is ignored, excused, and denied. Someone who has chosen not to believe in God can refuse to be convinced, even in the face of abundant evidence. However, this short cumulative case has shown that the existence of God is the most plausible explanation for the evidence. It is therefore more reasonable to believe in God than to reject Him.

[1]Paul Little, Know Why You Believe (Downers Grove, IL: InterVarsity Christian Fellowship, 1988), p. 23, citing Mortimer Adler, Great Books of the Western World (Chicago: Encyclopedia Britannica, 1952), p. 561.
[2]Phil Fernandes, No Other Gods (Fairfax, VA: Xulon Press, 1998), p. 236.

[3]This is an approach used by such Christian apologists as Phil Fernandes, Paul Copan, and Paul Feinberg. The approach presented here draws part of its outline from Phil Fernandes’ work, No Other Gods.

[4]C. Stephen Evans, Pocket Dictionary of Apologetics & Philosophy of Religion (Downers Grove, IL: InterVarsity Press, 2002), p. 30.
[5]William Lane Craig, Reasonable Faith (Wheaton, IL: Crossway Books, 1994), p. 83.
[7]Normal Geisler and Frank Turek, I Don’t Have Enough Faith to Be an Atheist (Wheaton, IL: Crossway Books, 2004), p. 95.
[8]Richard Dawkins, The Blind Watchmaker (New York: W.W. Norton, 1986), p. 115.

[9]Geisler and Turek, p. 98-102.
[10]Ibid., p. 106.

[11]J. P. Moreland, Scaling the Secular City (Grand Rapids, MI: Baker Books, 1987), p. 52, citing Paul Davies, God and the New Physics (New York: Simon and Schuster, 1983), p. 189.

[12]Geisler and Turek, p. 76-83.

[13]Ibid., p. 84, citing Rober Jastrow, God and the Astronomers (New York: Norton, 1978), p. 11.

[14]Fernandes, p. 72.

[15]Craig, p. 81.
[16]Ibid., p. 92, citing Theism, Atheism, and Big Bang Cosmology (Oxford: Clarendon Press, 1993), p. 135.

[17]Geisler and Turek, p. 37.

[18]Geisler and Turek, p. 175.

Written by

Brian Auten is the founder emeritus of Apologetics315. He is also director of Reasonable Faith Belfast. Brian holds a Masters degree in Christian Apologetics and has interviewed over 150 Christian apologists. His background is in missions, media direction, graphic design, and administration. Brian started Apologetics315 in 2007 to be an apologetics hub to equip Christians to defend the faith.

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