Many astronomers believe that the universe is all there is and that nothing exists outside it. Most astronomers today believe that the universe began with a huge explosion that has popularly come to be called the Big Bang. Astronomers likewise believe that all there was prior to the Big Bang was a small point of incredible density they refer to as the singularity. However, this singularity did not exist prior to the Big Bang. At that time, nothing existed. So if we were to invite some friends over, and watch an actual history of the universe in reverse, starting from today and going all the way back to just moments prior to the Big Bang, what we would see is all of the stars and galaxies simultaneously arriving at a single point, which would then disappear. In the words of the late prominent astronomer Fred Hoyle, the universe was "shrunk down to nothing at all.
Moreover, most astrophysicists believe that space and time likewise began at the moment of the Big Bang. Thus, there was not a place where someone could have witnessed the Big Bang or filmed it for DVD, since space did not exist prior to the Big Bang. When it happened, everything exploded into existence. In another sense, nothing exploded into everything. The Big Bang raises serious questions for atheist to consider because it seems to requires a beginning of the universe and a beginning seems to require a cause of some sort, at least for the vast majority of people who agree that everything that begins to exists has a cause. What caused the Big Bang?
If nothing existed prior to the Big Bang, not even space or time, then the cause of the Big Bang must be spaceless, immaterial, and timeless, infinite or eternal. It seems to be impossible to get something from nothing, at least by natural causes. And yet, if atheism is true, the Big Bang requires that the universe came out of nothing and was not caused. This places the atheist in a the difficult position of embracing a highly questionable philosophy, since science and all of human experience lead to the conclusion that things do not just come into existence without a cause.
Now there are atheists who disagree. Philosopher Quentin Smith unashamedly asserts, "The fact of the matter is that the most reasonable belief is that we came from nothing, by nothing and for nothing... We should... acknowledge our foundation in nothingness and feel awe at the marvelous fact that we have a chance to participate briefly in this incredible sunburst that interrupts without reason the reign of non-being." When I read statements like this, my faith may be increased due to rather ad hoc explanations that skeptics make in order to rationalize the data.
It seems, then, that the existence of the universe is impossible without an eternal and immaterial cause. Thus, the scientific argument for some sort of first cause looks like this: 1. Everything that begins to exist has a cause. 2. The universe began to exist. 3. Therefore, the universe as caused. When I reflect on the nature of the cause, I find that it must be immaterial and timeless. From the nature of complexity it would seem that the Designer would have to be extremely intelligent. Some would call this cause God. Although I can't argue this issue further at this point, what I see certainly seems to favor the case for theism over the case for naturalism. Keep in mind that the above arguments for God do not prove the Christian God. However, the Creator is strikingly consistent with him.