Is it possible that the universe could be eternal??...

[Anomalocaris]

It depends on what you mean by "eternal". If you mean "for all time" then yes, since current theories state that time itself began with the Big Bang, which was the expansion of space/time and the "start" of the universe we live in.

If you mean instead "for infinity" (i.e. no start, no end) then the question is rather unanswerable, although it does form several philosophical questions, such as how you can ever get to a finite point in time (as we experience) when you have no reference on the infinite timeline.

What if I told you The Big Bang Theory is just Roman Catholic Propaganda that is wanting in terms of evidence.

If you told us that then we would know you are a stupidly self-important but deeply ignorant and dishonesty would be huckster