The Case for Theism

[Jackalope]

The Big Bang theory states that the universe started from a singularity.

(I realize that you almost certainly know this, but the language you're using here is imprecise and I'd like to avoid confusion with other readers.)

That's not what it says at all. It states that if we apply the known laws of physics to our observations and wind time backwards to the Planck Epoch, then the state of the universe would be a singularity. However, we cannot say anything about the "starting" of the universe - if a singularity existed, then it literally WAS the universe, just not in the form we know today. We know nothing about the start of the universe, if it started at all - or even if temporal concepts like "start" are even meaningful in that era.