I think that really what it is getting at is the fact that some people do not think the truthfulness of their position is as self-evident as their rhetoric claims, since otherwise they would not be opposed to their children and those under their influence thinking and exploring freely.
As someone who is religious but who prioritizes truth above all else, I would say that the search for truth should take priority over any traditional truth claims that human beings may have adhered to. If truth is of paramount importance, then we won’t object to having to change our views when evidence requires it, whether those views have to do with matters of theology or astronomy or anything else.
Despite what the Lovecraft quote claims, it simply isn’t the case that all religion adopts the sort of program of indoctrination he suggests. Among Deists, liberal Protestants, and many other sectors of religion, there has been not merely an openness to but a pioneering quest for truth even though it challenged religious beliefs that those engaged in that quest may once have held dear.
The problem is not “religion” in some generic sense, but any religion that is opposed to an unbending quest for truth.