Hi Phat -
If the universe always existed, that seems to set better with folks than asking if God always existed. Folks usually ask "Who created God?" but never seem to mind the fact that a singularity was sitting around for eternity until the explosion.
I think the relevant argument is that if we insist on the need for a creator for the Universe, we must also insist on the need for a created creator. But if we are happy to relax the point, and accept that the Universe could exist without the need for a creator, that then allows us to consider also an uncreated creator...
Cavediver, if the universe had no beginning, what is the purpose of our lives if we may someday be compressed back into a singularity?
I don't know about purpose, but you are a fixed permanent immutable part of our Universe. Your limited span of time merely fixes your position in the 4d space-time. In the same way that you cannot expect to be at all places in the Universe, nor can you really expect to be at all times. That doesn't diminish your role...