The Cosmological Argument
The
cosmological argument is the argument from the existence of the world or universe to the existence of a being that brought it into and keeps it in existence. It comes in two forms, one modal (having to do with possibility and the other temporal (having to do with time).
The modal cosmological argument, the
argument from contingency, suggests that because the universe might not have existed (i.e. is contingent), we need some explanation of why it does. Whereever there are two possibilities, it suggests, something must determine which of those possibilities is realised. As the universe is contingent, then, there must be some reason for its existence; it must have a cause. In fact, the only kind of being whose existence requires no explanation is a necessary being, a being that could not have failed to exist. The ultimate cause of everything must therefore be a necessary being, such as God.
The temporal
kalam cosmological argument, begins by arguing that the past is finite. The idea that the universe has an infinite past stretching back in time into infinity is, the argument notes, both philosophically and scientifically problematic; all indications are that there is a point in time at which the universe began to exist. This beginning must either have been caused or uncaused. It cannot have been uncaused, though, for the idea of an uncaused event is absurd; nothing comes from nothing. The universe must therefore have been brought into existence by something outside it. The kalam argument thus confirms one element of Christianity, the doctrine of Creation.
The Teleological Argument
The
teleological argument is the argument from the order in the world to the existence of a being that created it with a specific purpose in mind. The universe is a highly complex system. The scale of the universe alone is astounding, and the natural laws that govern it perplex scientists still after generations of study. It is also, however, a highly ordered system; it serves a purpose. The world provides exactly the right conditions for the development and sustenance of life, and life is a valuable thing. That this is so is remarkable; there are numerous ways in which the universe might have been different, and the vast majority of possible universes would not have supported life. To say that the universe is so ordered by chance is therefore unsatisfactory as an explanation of the appearance of design around us. It is far more plausible, and far more probable, that the universe is the way it is because it was created by God with life in mind.
http://www.philosophyofreligion.info/theistic-proofs/
These are my personal favorite classical arguments. There are more arguments like the ontological argument and the moral argument, yet I find these above to be more tangible.
From a different site:
Believe it or not, a 5 year old child could be an atheistic scientist's worst nightmare by merely asking him “where did everything come from if God didn't make it?” What that child is actually asking in scientific terms is “how do we have a violation of the 1st Law of Thermodynamics by the creation of energy and matter in the closed system of the universe if there is no Creator capable of doing that?”
Plain and simple, matter/energy can not come into existence. It is scientifically impossible, yet here we see everything around us, so how can that be? There are really only 3 possibilities. Option A: Everything came into existence by itself anyway, without the help of God, (even though science has proven that impossible). Option B: Everything in the universe has always existed for all of eternity, (which, by the way is also scientifically impossible as explained in the Top Ten Proofs for God's Existence CD due to something called the 2nd Law of Thermodynamics), or Option C: There must be a God, a Being greater than science, who created the Laws of science and has the ability to disobey them. Not only is a belief in God the only logical conclusion to draw, it's the only one scientifically possible because remember, if there is no God, the first two options are scientifically impossible according to the actual Laws of Physics.
http://toptenproofs.com/article.php?id=7
This one is rather simple and more of a modern idea. To understand more fully take the link to the site and read the whole article. It is a short read.
