1) Christianity
2) Maybe. I'm not completely sure and I guess it's one of those things where you never can be.
3) I don't know how else to describe it than as this amazing peace and joy just surrounding you.
4) I don't know. I hope so. I know there is some profound truth to the message of Christianity but I don't know how concrete it is, if that makes sense. I don't think there's an "old bearded guy sitting on top of a cloud", but I don't think it's all purely metaphorical either. If there is such a person as god, I don't think I will ever meet him as me being the me I've grown used to while living on earth.