What you're talking about is called Pascal's Wager I believe, because it's an argument that Blaise Pascal originally forwarded. It's interesting, but I believe there are certain flaws in the logic.
Firstly, if you believe something only because you think believing it will have a good outcome, is that true belief? Will self-delusion for the sake of personal gain get you into heaven?
Secondly, assuming God exists, how do you know what kind of God is up there and what kind of standards he has set for humankind? He may not be the God of the Bible, but instead the exact opposite, sending believers to hell and heathen to heaven. (Just a hypothetical situation.
) If God does exist, then who's to say he has any concern whatever for what you believe? In fact, if we take his creation as evidence of what he is like, the he probably rewards those who use what he gave them to use: eyes and ears, a rational mind, sexual organs, and the capacity for doubt.