Not too long ago, I read the very thought-provoking Religious Literacy: What Every American Needs to Know and Doesn't, by Stephen Prothero, likely because it came recommended by Dale McGowan. The discussion of the history of religious education in the US is fantastic.
The main argument of the book is that, until recent decades, we knew quite a lot about Protestantism, through instruction at home, in churches, and even in the school system. People apparently used the verb "catechize", as something you did to children. But this knowledge of what's actually in the Bible, and actual church doctrines is, these days, largely lost on us in the US, even though we're very caught up in our religious identities and church attendance is huge.
Political discourse is full of religious allusions, but we often don't get the references. I would have appreciated more examples of problems that this causes in practice -- is it really an issue for being a citizen in a democracy?
Prothero notes, early on, that Europeans are much less religious than Americans but more familiar with religious content. Dale McGowan says "faith is most easily sustained in ignorance"; knowing a thing or three about a few different religions makes it easier to not get caught up in any of them. Is the major problem caused by religious ignorance that it makes it easier for preachers and politicians to jerk people around by telling them that God says thus-and-such?
While Prothero doesn't address the question of why the more broadly-educated Europeans don't tend to be churchgoers, he does put forth a policy suggestion, that our curricula should have more information about the world's religions. And while I agree that it's probably a good idea, he doesn't say much about the sorts of changes we might see, with better religious studies education. I must admit, I have a hard time thinking of education-about-religion as anything except a strategy against the influence of seemingly-devout people.
Perhaps I'll pick up his more recent book, God Is Not One, about the fundamental disagreements between different religions, contrasting with the framing you'd get from Huston Smith or Karen Armstrong, who argue that different religions are grasping towards the same fundamental truth. I'm really curious about his personal position, because Prothero identifies himself as an Episcopalian, but hasn't thus far talked about any particular benefits of people believing any particular thing.