Kevin, on the other side, I'd say that your skepticism is well-founded. There are hundreds of stories about God and Gods. The Biblical accounts of the creation of a young earth, if taken literally, do not coincide with the physical evidence. The entire concept of Satan, indeed, makes no sense. An omnipotent God could eliminate Satan in a blink of an eye. As to the question of what happens when you die, consider what it was like to "be" before you were born. That's what I figure death is like.
Finally, whatever you believe, do not be afraid of your convictions, and don't be ashamed to say what you are. I wouldn't go blabbing to your Grandparents, that would be needlessly traumatic, and not worth it. But I would be honest with anyone who asks. There's nothing wrong with religious diversity, and this forum is better off for all the voices it has.