What imagery calls to mind freedom from religion?

As a Web developer, most of my assignments are quite straightforward. Whether it’s a site for a surf shop, sunglass maker, PC supplier or you name it, it’s dead easy to guess what search terms will produce some killer images on a stock photo website. I download comping copies of some photos, throw in some Photoshop magic, and I’ve got a set of several comps (design studies) I can show the client. They either buy off the one they like, or come up with some ideas for tweaks, and soon we have a clear idea of the look and feel we want to give their site.

But now I have a client that is advocating for people to live without religion. I went to my favorite stock photo agency’s site tried search terms like new age, atheism, atheist, agnostic. Nothing jumps out as making sense. Searching religion tends to produce images tailored to one particular faith or another. Nothing there either. What sort of images would you associate with a non-profit organization promoting the idea that we can live without religion?