As an atheist, I always found it rather humorous that christians use the big bang as a support for their religious assertions of a deity creating something out of nothing.

There is a reductionist question at play here- if a deity created the universe, who created the deity? The religious answer is that the deity always existed.

I find it odd that they can accept and believe in an all powerful ever existing being but can't accept the concept of an ever-existing universe. Their assertion is you can't have something created out of nothing.

I tend to adhere to a hypothesis that there wasn't just one "big bang." The universe always existed. The material in the universe 'banged' and expanded, then contracted to a point where it blew up again- another bang. repeat repeat

This repeat hypotheses is called the "big crunch."[1]

[1]

https://www.scientificamerican.com/article/will-the-universe-ever-stop-expanding1/#:~:text=%E2%80%9CIt%20goes%20from%20causing%20the,That's%20called%20a%20big%20crunch.