What is Religion?

[blahblah18]

Now this isn't a religious debate, so untwist your panties.. .although i'l lbe starting one of those soonish. This is just something i've been discussing with a friend of mine who is a Religious Studies major for a while now.

what is religion? What does it mean to be a religion? what is it defined as?
He argues that people that dress upin the same garb every day to go to every red sox game and center their lives around it should be considered followers of that religion, whereas I feel that there needs to be some form of interaction or at least idea of a spiritual almighty, but then the more i thought of it, there are quite a few religions that have no mention of any supreme being (Janism, Buddhism to a lesser extent). So, what does it mean to be a religion?