I once heard in a sales seminar that fear of loss is a greater motivator than opportunity for gain.
If I am wrong, and there is no God, what have I lost? Nothing.
If the atheist is wrong and there is a God, what has he lost? Everything!
And not only have you lost nothing by believing in God, the rest of society has probably received better behavior from you in general for the time you did believe in God. Because you were trying to live as you understood God wanted you to live with others.