I think it is a wonderful blessing that we live in a country where we can have freedom of religion and speech and have these debates. Religious persecution is still rampant in many parts of the world. People are dying for their beliefs every day, while we worry in America about "being offended" and achieving "Freedom FROM Religion", and getting all in a huff about someone putting a bible tract or the like in a tupperware container in the woods. I think this is the same part of the brain that panics when it can't find the remote control, or complains when their McFries or a little too cold.
Being easily offended is a sign of weakness. Take that however you would like. I don't care--I don't get offended!
That being said, I would also like to give my brief opinion on Bible tracts and the like. If anyone should be offended by bible tracts and religious advertising left in geocaches, it is Christians. No one has ever been converted or accepted Christ by getting a tract shoved in their face, or left in a geocache. It's the junkmail of Christianity. If you want to represent Christ, show love the way Christ did. If you come upon a cache in disrepair, fix it up. If you open the cache and it is filled with junk, replace it with some nice stuff. Treat nature with respect. Treat private and public property with respect. Practice Cache In-Trash Out. Live life in the service of others, helping those who deserve it and those that do not, and if someone is seeking and they ask you "why you do what you do", then share with them the message. A lot more "effective" than unsolicited junkmail. But if someone feels this is how they would like to share the message and spread the word, it won't offend me, just disappointed that there is one less matchbox car, dollar store action figure or McToy treasure for my kids to choose from.