Behind critical studies of religion (which were mostly led by scholars with a religious commitment then, and are still mostly led by scholars with a religious background now) there may sometimes be more than the purely "ascetic ideal" of science (as Nietzsche puts it, observing that even this ideal itself is basically religious). There is also, in many cases, a kind of paradoxical religious quest -- to dust off, revive, refresh, renew what old dogma has eventually obscured and buried for preservation sake. Sometimes it's the priests (or prophets) themselves who set the old temple on fire (and the fire of the burning temple is still sacred fire in a sense) in the hope that what old words and notions stood for and thus concealed will "resurrect" and be manifest again, even better, phoenix style. With the obscure faith that there is something indestructible deep beneath the surface they destroy (all the more eagerly). That the truly sacred is not threatened by sacrilege but by routine and indifference.
In the long history of religion it is not a rare occurrence that a new faith rises from the destruction of an older one. What post-exilic Judaism did to old Israelite religion, Buddhism did to Hinduism, Christianity to Judaism, Islam to Eastern Christianity...