Daniel Dennett, answered from the texts and cited to the page.
Religion is a natural phenomenon — a set of human behaviors, beliefs, and institutions that arose through cultural evolution from antecedent cognitive and social mechanisms — and is therefore a legitimate object of scientific study using the standard methods of evolutionary psychology, cultural memetics, anthropology, and cognitive science.12
Religious experience is real as experience; specific theological claims (the existence of personal gods, the truth of miraculous events, the supernatural origins of holy texts) are empirical claims that mostly fail under examination. Belief in belief — the second-order commitment to the value of believing — is a distinct phenomenon from genuine first-order belief, and much religious activity is best understood as belief in belief rather than belief proper.345
There was a time, not so very long ago by evolutionary standards, when there was no religion on this planet, and now there is lots of it. Why? It may have one primary evolutionary source or many, or it may defy evolutionary analysis altogether, but we won't know until we look. Do we really need to inquire about this?Breaking the Spell - Religion as a Natural Phenomenon, p. 84
I might mean that religion is not an artifact, not a product of human intellectual activity. Sneezing and belching are natural, reciting sonnets is not; going naked—au naturel—is natural; wearing clothes is not. But it is obviously false that religion is natural in this sense. Religions are transmitted culturally, through language and symbolism, not through the genes.Breaking the Spell - Religion as a Natural Phenomenon, p. 38
That is the main question I will address here, and once we have sorted out and clarified (not settled) some of the conflicting answers to this question, it will give us a novel perspective from which to look, briefly, at the traditional philosophical issue that some people insist is the only issue: whether or not there are good reasons for believing in God.Breaking the Spell - Religion as a Natural Phenomenon, pp. 41–42
We would never let business tycoons get away with saying that since we weren't plutocrats ourselves we couldn't hope to understand the world of high finance and were hence disqualified from investigating their deals.Breaking the Spell - Religion as a Natural Phenomenon, p. 271
They know that they share the planet with others who disagree with them, but they don't want to enter into dialogue with those others. They want to discredit, suppress, or even kill those others.Breaking the Spell - Religion as a Natural Phenomenon, pp. 37–38
The position is fully developed in Breaking the Spell (2006). I was billed with Dawkins, Harris, and Hitchens as one of the "Four Horsemen" of the New Atheism but I have always resisted the polemical label — Breaking the Spell is diagnostic rather than polemical, and I distinguish my project from Dawkins's and Harris's on the question of whether religion is on net harmful (I think the empirical question is open).