Well, I do wonder about that. Why do theists care so much about belief in God? Disagreement over that question is really no more than a difference in philosophical opinion. Specifically, it’s just a disagreement about ontology — about what kinds of things exist. Why should a disagreement like that bear any moral significance? Why shouldn’t theists just look for allies among us atheists in the battles that matter — the ones concerned with justice, civil rights, peace, etc. — and forget about our differences with respect to such arcane matters as the origins of the universe?From reading the rest of the interview one does not get the impression that Antony is a hard-shell religion hater, and her observations in this answer reflect a real puzzlement about why theists frequently take their theism so intensely seriously. What's the big deal? It is a good question honestly asked. It deserves an answer.
But I'm not sure that there is an answer that is really going to make sense to her. Earlier in the interview she implies that religious belief systems are all based on rationalizations rather than on rationality as she understands it. What she considers "reasons" for believing are largely "the result of automatic unconsciousness processing, involving lots of unarticulated judgments." She apparently feels that beliefs are an inferior way at arriving at truths based on a-rational considerations. Her puzzlement and views on believing, if I've read them correctly point to a gap in understanding between theists and non-theists concerning the nature of reality that seems almost impossible to cross. On the theist side of the gap, we make connections that make little sense on the other side. Let me be clear that I am not talking here about hard-core religious fundamentalists who, in truth reside in another corner of reality much closer to hard-core atheists than to the rest of us. Both of them live on the other side of another chasm, between dualist/absolutist and non-dualist/relativist ways of thinking, which is if anything wider and deeper than the one between theists and non-theists generally.
So, in any event, it appears almost impossible to explain to Antony in ways that she would comprehend why our faith in God is so important to us or why there is far more at stake for us than a "difference in philosophical opinion." We can agree with her that we should seek allies among the non-theists when it comes to the struggle for a more just and peaceful society, but be that as it may fundamental questions about the origins and nature of reality are not merely "arcane matters" to us—even those of us who are not intent on defending a seven day creation myth or taking literally cherry-picked dogmas and prejudices from an ancient text that requires a wiser reading than it frequently receives.
It may be that in another entry here I will try to answer Antony's questions about why our faith in God is so important, but before trying such a thing it is important to acknowledge that the answer probably won't be of much help to her. There is a gap that is really difficult to cross. What is to be appreciated is that while she doesn't understand theist thinking she is reasonably respectful of it. That, at least, is a start.