The following is a proof for the existence of the God of the Bible. It is an adapted and modified version of a proof given by Norman Geisler in his "Christian Apologetics". I have mostly used logical deduction and self-evident facts, with minimal resort to empirical evidence. The main components of the arguments are in bold blue type, numbered in upper-case. I don't claim that this proof possesses mathematical rigor. It does show however, that belief in God is more rational than its alternatives. "But I insist on mathematical style proof!"
FIRST: Systems of rules imply one or more rule makers and rule enforcers. We find this to be true wherever the origin of the rules is clear. For example, traffic is governed by rules, and there is a traffic department that makes and enforces the rules.
A contingent thing is defined as a thing having at least one of the following attributes:-
It had a beginning in time
It is not in complete control of itself
These features indicate that contingent things are governed by rules that they have not set for themselves. For example, I am not in complete control of myself. I cannot decide to live for 200 years. This illustrates that I am subject to rules of body decay that I have not set myself - I cannot help these rules; I have to live with them whether I like them or not.
Below, I discuss the cause of the existence of contingent beings. In this connection, a couple of clarifications are in order.
Firstly: A common mistake is to confuse the description of a phenomenon with its cause. As an example, suppose we ask the average person: "Why does the earth keep going around the sun?" The common response is: "The law of gravitation makes the sun keep pulling the earth toward itself". But this is wrong. The law of gravitation only describes what the sun does - it does not cause the sun to do what it does any more than a weighing machine makes you gain weight.
Why does the universe exist? The answer "Because the laws of physics decree so" is wrong. The laws of physics are only principles describing what happens. They don't cause the happenings.
Secondly: Another common mistake is to confuse the cause of the existence of something with the instrument or mechanism that was involved in bringing it into existence. For example, my parents brought me into the world, but they are not the cause of my existence. This can be seen by noting the following:-
In the same way, the artist is not the cause of the existence of a painting, the engineer is not the cause of the bridge, etc.
Thirdly: Existence is not a once-for-all package deal. Existence is be-ing (continuous) and therefore requires a continuous cause. A true cause of existence is current - a cause of be-ing, not a mechanism of be-coming.
Since contingent things like you and I exist, it is appropriate to look for their cause. We have three self-evident, mutually exclusive and exhaustive possibilities:
That leaves us with the remaining (third) possibility, which becomes the second point of my main argument:-
SECOND 3. Every contingent thing is currently caused to exist by another
THIRD: There cannot be an infinite regress of current causes of existence - let me justify:-
An infinite chain of contingent beings must itself be contingent and so cannot avoid the question of what caused it. [To illustrate: if a five link chain needs a peg to hang, a chain of infinitely many links cannot avoid a peg]
Another way to see that an infinite regress is not possible is to realize that even a single causal link between two contingent beings is impossible. A contingent being is the effect as far as its own existence is concerned. It therefore cannot be the cause of the existence of another being: If I cannot ensure that I exist, I certainly cannot ensure that something else exists, because that would mean exercising total control over something using resources over which I do not have total control.
FOURTH: There cannot be a first cause that caused itself. Such a being would have to bring itself into existence (that is, do something) before it existed. This is self-contradictory, and thus false.
FIFTH: Therefore a First Un-caused Cause of my current existence exists.
SIXTH: This uncaused cause must be
SEVENTH: Thus, the uncaused cause should be infinite in all His attributes. A finite entity would be contingent.
EIGHTH: Thus, the uncaused cause is infinitely good. How do we know that He is not infinitely bad instead? Couple of reasons:
There is at least some good in the world - an infinitely evil, infinitely powerful being would not permit this. Then why is there evil today?
A rapist wants sex, which, by itself, is good. Hitler was bad, but he was not purely bad. He had a great vision for Germany. Bad people do bad things claiming that what they are doing is good. What we understand as bad is just a wrong combination of things that are good in themselves. Thus, pure badness does not exist. So, our First Cause is not infinitely bad.
Thus, the uncaused cause is infinitely good.
NINTH: This being is unchanging. If it were possible for Him to change, it would mean that He has the potential to be something that He is not now. But since He is infinite in His existence, He is all that He can be now! Thus, He should be unchanging.
TENTH: This being exists in a plurality of persons [What does this mean?]. This is because a plurality of infinite persons is needed to validate infinite goodness and infinite love.
ELEVENTH: This infinitely perfect being is appropriately called God.
TWELFTH: Thus, God exists.
THIRTEENTH: This God who exists is identical to the God described in the Bible. We can see this from the attributes of the God of the Bible.
FOURTEENTH: Therefore, the God of the Bible exists.
As explained above, the fact that the universe exists and that a contingent thing requires a cause can be used to conclude that this universe requires an Infinite Cause - God. The argument sounds a lot more convincing if our universe had a beginning (although I have not assumed it). The current atheistic explanation for the universe is the Big Bang Theory. In its simplest form, it implies a beginning for our universe (that is why atheists found it repulsive when it was first propounded!). The following are some ways that atheists have suggested to escape the above arguments and/or maintain an eternal universe in a Big Bang context and my responses to them:-
This universe just popped into existence - a quantum fluctuation. But this means that there was something to fluctuate. The "quantum vacuum" posited by these atheists is not nothing, but a lot of matter-antimatter potential - which requires a Cause. Thus, this atheist argument does not save the atheist claim that nothing resulted in something.Oscillating universes: our universe is merely one in a cycle of endless big bangs and big crunches. However, this is just speculation. As far as we know from physics, ‘There is no known physical mechanism to reverse a catastrophic big crunch.’ - Tinsley, B., 1975. From Big Bang to Eternity? Natural History Magazine. October, pp. 102–5. For the cycle to go on endlessly without reaching "heat death", the second law of thermodynamics has to be violated - a miracle.
Okay, failure admitted, but isn't theism also illogical in talking about what happened before the creation of the universe (with which time began)? No, the Bible says that God created the universe in the beginning (not before the beginning - Genesis 1:1). To borrow from William Lane Craig: The first moment of time is the moment of God’s creative act and of creation’s simultaneous coming to be. This is an example of simultaneous causation - the "textbook example" is due to Immanuel Kant: a weight resting on a cushion simultaneously causes a depression in it.
Belief in a God is the only rational explanation for what we see all around us. Atheists argue that all explanations for reality must be grounded in the laws of science alone. However, atheistic origins theories such as the Big Bang Theory and Organic Evolution themselves violate physical laws (all the laws at the moment of the Big Bang, and the laws of biogenesis and information theory in the case of organic evolution). Thus, the atheist position is self-contradictory.