Heaven and Hell don't exist!?!?

Last night when I was pondering upon God's word in Psalm 8, a question pops into my head (from one of Chrisye's songs), and it keeps me thinking. I can reflect back through my life and motivation of living a Christian life.

The question is : If Heaven and Hell do not exist, how would you lead your life?

The assumption is everything else is still the same. There would still be church, christian, God, Jesus, etc.

But can you take some time and think back:
1. If heaven and hell doesn't exist, would you accept Jesus into your life as your God and savior?
-- If you receive Him as your God, means He will rule over you. Would you still do that?
-- The alternative would be: you can do whatever things you want in this world.
2. Would you still come to church every week?
-- Even if you come to church every week, you won't get into the Heaven because there is no Heaven.
3. Would you still serve at church?
4. Would you still lead christian life (e.g.: integrity, honesty, love each other, love your enemy, etc.)?
5. Any other questions that can pop into your head.

These questions made me think deep, what is it that made me become a Christian. Or more precisely, what keeps me being Christian.

How about you? Would you still be a Christian if there are no Heaven or Hell?