The Argument of Contingency
The is a very straightforward logical premise.
If something exists, there must exist what it takes for that thing to exist.
The universe—the collection of beings in space and time—exists.
Therefore, there must exist what it takes for the universe to exist.
What it takes for the universe to exist cannot exist within the universe or be bounded by space and time.
Therefore, what it takes for the universe to exist must transcend both space and time.
Something is “necessary” if it could not possibly have failed to exist. The laws of mathematics are often thought to be necessary. It is plausible to say that mathematical truths such as two and two making four hold irrespective of the way that the world is. Even if the world were radically different, it seems, two and two would still make four. God, too, is often thought to be a necessary being, i.e. a being that logically could not have failed to exist.
Something is “contingent” if it is not necessary, i.e. if it could have failed to exist. Most things seem to exist contingently. All of the human artefacts around us might not have existed; for each one of them, whoever made it might have decided not to do so. Their existence, therefore, is contingent. You and I, too, might not have existed; our respective parents might never have met, or might have decided not to have children, or might have decided to have children at a different time. Our existence, therefore, is contingent. Even the world around us seems to be contingent; the universe might have developed in such a way that none of the observable stars and planets existed at all.
Dr William Lane Craig puts it like this:
"What would be something that exists by a necessity of its own nature? Well, many mathematicians think that numbers exist in this way. Things like 0, 1, 2, 3, and all of the rest of the natural numbers. By numbers here I don’t mean these marks on the whiteboard, but I mean the numbers themselves. The quantities themselves – 1, 2, and 3. Or many mathematicians think that sets exist, like this set which has one member, namely the number 0: . They would say there are an infinite number of sets. Or mathematical functions like the F(a) is a function. Or geometrical shape like a square or a circle. They would say that these things are things that actually exist. Mathematicians often think that these things are real, and if they exist they don’t have any causes. They are not contingent; there is no cause of the number 3. There isn’t any cause of the set of all space-time points. These simply exist through a necessity of their own nature. Mathematical objects are necessary beings."
This cosmological argument for God can go even further when examined from the perspective of astrophysics. Recent discoveries by Guth-Vilanken, which I mentioned in other arguments, show us that the universe, is in fact, not eternal. Therefore, the contingent matter that began, in the Big Bang (if that's what you perceive to believe as a hypothesis), needs an explanation that is necessary.
The universe's matter and energy cannot be the necessary component. If all of this matter and energy is necessary and thus eternal, we are implicitly assuming that the laws of Conservation of Energy and Conservation of Mass held both at the time of the Big Bang and before. in order for matter to be eternal, all of the underlying particles would not be able to stop existing. But quantum mechanics suggests that this is not so. In fact, it is even the case that, under quantum mechanics, the law of Conservation of Energy is violated. It seems utterly ridiculous to think that matter and energy in a constant state of fluctuation, even popping in and out of existence, are necessary and eternal.
Now, as a theoritical thinker, I can portray a universe that has sub-necessary objects (matter and energy for life) but these subsets are both necessary and contigent, still requiring an absolute necessary being, namely God.