It is true that a small change in the strength of the four known forces would imply that stable protons and neutrons, the basis of atomic nuclei, might not exist. (The universe, however, would—a rather large error in the Metaxas piece.) This is old news and, while it’s an interesting fact, it certainly does not require a deity.Whenever I think about these claims that this or that is so unlikely that God must have intervened, I remind myself that whatever the odds, something had to happen. After all, the odds against you sitting in your chair right now reading this would require a page of zeroes to express, even in scientific notation. (Your parents' genes could have combined in trillions of different ways; and their parents'; and their parents' before them . . . ) And yet, here you are. Pleased to meet you. Do you prove the existence of God?
Once again, Metaxas confuses cause and effect. The constants of the universe indeed allow the existence of life as we know it. However, it is much more likely that life is tuned to the universe rather than the other way around. We survive on Earth in part because Earth’s gravity keeps us from floating off. But the strength of gravity selects a planet like Earth, among the variety of planets, to be habitable for life forms like us. Reversing the sense of cause and effect in this statement, as Metaxas does in cosmology, is like saying that it’s a miracle that everyone’s legs are exactly long enough to reach the ground.
Another thing I notice about arguments like Metaxas' is that he never asks what are the odds against the existence of a God who decides to create a universe exactly like this one, with us in it. He would probably respond that my question is absurd. And I agree.
Some things are mysteries, and likely always will be.