The Kalam Cosmological Argument
The kalam cosmological argument asserts that:
- Everything that begins to exist has a cause.
- The universe began to exist.
Therefore: the universe has a cause. Those arguing this position usually go on to argue that this cause is God.
In support of #2, the usual argument is that the past must be finite. This is justified by various arguments showing that an infinite past is absurd. It turns out that one way of viewing Mormonism's claims requires an infinite past (not necessarily of this universe, though; possibly of some kind of metaverse containing our universe).
Once upon a time, when the world-wide web was young, I had a page containing a bibliography of online articles and sites that discussed the kalam cosmological argument. Years have passed, and most of those sites are gone. Furthermore, there is a much better discussion of the topic now available on wikipedia. Go read!