Religions attempt to describe that which is indescribable. Their descriptions can only be an approximation of the thing they are trying to describe. That's okay, because these descriptions are guideposts that help people find the way to the thing that can't be described. Different religions provide different sets of guideposts to the same thing. We choose the religion whose guideposts help us find the way. Because we have different cultures and different personalities, different people find different sets of guideposts helpful.
The problem comes when people take the guideposts to be the destination. We need finite representations to help us find the way, but we should not treat the finite representations as the end goal. To do so would be idolatry.
A religious message is a finite expression of an infinite idea. Religious messages need to be understood as metaphors for that which can't be made concrete. They should not be taken literally. When they get taken literally is when the damage ensues. Religion gives us some guidelines for how to live in order to get in touch with the infinite. Different religions have different guidelines. Even though the roads are different, they all have the potential to get to the same place. But when people take the guidelines too literally, they end up losing the core message that the guidelines are supposed to lead to. The core message of religions is to treat other people with love. When people start taking the guidelines as an end in themselves, they end up condemning people who don't follow the same guidelines, and sometimes doing violence to those people as a way to save the world from the evil infidels. When they do this, they are acting against the core message that the guidelines were supposed to get them to. That's why idolatry is wrong, because if you make the guidelines into the end goal, you end up violating the thing that should have been the end goal.
It's also bad when anti-religious people take religious messages too literally. If they think the religious messages are supposed to be literally true, then when they see that they can't be literally true, they say that religion is just all ridiculous and wrong. In the movie Religulous, Bill Maher says to a Senator who admits he believes in the story of the Garden of Eden, "It worries me that people are running my country, who think, who believe in a talking snake. " I guess there are actually people who do believe in taking the Bible so literally. But I don't think it should be taken that way. I think it should be taken metaphorically. A story doesn't have to be literally true in order to convey a valuable message. When people think that religion can only be understood literally, and then reject it as ridiculous on those grounds, to me it's like they haven't even seen what religion is supposed to be. Speaking of metaphors, here's an example: Imagine you have a recipe for muffins that says bake for 20 minutes. You bake for 3 minutes. Then you taste the muffin and you find it rather wet. Based on this, you decide that all muffins are terrible, and anyone who eats muffins is a fool. But you haven't even seen what muffins are supposed to be. That's what it's like with some people who reject religion -- they look at the way people have incorrectly interpreted religion, and when they don't like what they see, they reject all religion on that grounds.