Mathematician, physicist and cosmologist Frank Tipler is one of the most accomplished scientists in his field. Together with John Barrow he co-authored a definitive treatise on the anthropic principle, titled The Anthropic Cosmological Principle, and has been outspoken in his criticism of attempts to avoid the theological implications of the Big Bang and the fine-tuning of the universe.
In the video below he discusses cosmic fine-tuning, the multiverse and some related topics, but the most striking issue he takes up is the nature of the singularity that gave rise to the Big Bang and to the space-time universe we inhabit. According to what's called the standard model the universe arose from an infinitely dense point called a singularity, and Tipler claims that the singularity must be, by definition, a supernatural being.
What's more, although he doesn't develop this as much in this short segment as I would've liked, he insists that the singularity must also be rational.
A rational being which transcends space, time and matter and from which the entire universe emerges sounds an awful lot like the theist's conception of the God of creation.
This conclusion makes naturalist physicists very uncomfortable which is why, Tipler maintains, there have been so many attempts to explain the origin of the universe without invoking a singularity at its beginning. It's Tipler's contention, however, that every one of these attempts lacks empirical support. They're not good science, but are, rather, little more than speculative products of physicists' imaginations.
The video is eleven or so minutes long, but if you're interested in the theological implications of the origin and fine-tuning of the universe, you'll find it a very interesting eleven minutes: