Be careful not to confuse Christianity and religion with God because it only attempts to formalize some eternal truths and give people (who are too lazy to think for themselves) a set of rules and guidelines that they 'must' follow.
It's undeniable that you have a spirit and that you are indeed a spiritual being having human experiences. Life and the experience of being on this earth in this body is nothing but a temporary experience. You came from the world of spirit (eternity) and to it you will return the second you leave your form.
The whole heaven and hell thing was an invention by the early churches to instill fear in people - they understood one psychological fact very!
