As for the actual argument, it’s the same old stuff religious apologists have been croaking out since the days of Bertrand Russell namely that because science is inadequate to explain the mysteries of existence, faith must be necessary. Life would be meaningless without religion, therefore we must have religion.
But this sort of thinking is exactly what most agnostics find ridiculous about religion and religious people, who seem incapable of looking at the world unless it’s through the prism of some kind of belief system. They seem to think that if one doesn’t believe in God, one must believe in something else, because to live without answers would be intolerable. And maybe that’s true of the humorless Richard Dawkins, who does seem actually to have tried to turn atheism into a kind of religion unto itself.
But there are plenty of other people who are simply comfortable not knowing the answers. It always seemed weird to me that this quality of not needing an explanation and just being cool with what few answers we have inspires such verbose indignation in people like Eagleton and Fish. They seem determined to prove that the quality of not believing in heaven and hell and burning bushes and saints is a rigid dogma all unto itself, as though it required a concerted intellectual effort to disbelieve in a God who thinks gays (Leviticus 20:13) or people who work on Sunday (Exodus 35:2) should be put to death. They’ll tie themselves into knots arguing this, and they’ll probably never stop. It’s really strange.