The Kalam Cosmological argument.

[neil]

I don't believe the universe began to exist.

Ok, then. Question to you: What existed 100 BN years ago?

a) Nothing. And if so, then everything came from nothing.
b) Nothing material, i.e. an Immaterial Spiritual Being.

Atheism is forced to hold on to a. Defenders of Kalam say b.

We know the Universe began to exist because we know its finite age.

Whereas the God of Christian Revelation has always declared Himself Eternal.

Neither "a" nor "b"; to me, the universe existed essentially no differently 100 billion years ago from the way it exists today.

I don't believe the universe has an age (other than infinite), and (thus) I don't believe that we actually know its finite age.

BTW I don't identify as atheist; I'm non-religious.