Do you really believe this stuff? Do you really believe there's a place called heaven? And do you really believe what the Bible says that Jesus is the only way to heaven? Three reasons we don't share our faith:
1. We feel disqualified - I have a past. I have a present. God can't or won't use me.
2. We feel unqualified - I don't know all the stuff. I don't know what to say. God probably shouldn't use me.
3. We don't really believe this stuff
I know that's a strong statement, but think about it... if we really believe in heaven and hell and don't share that, I mean c'mon. And if we really believe that identify in Christ is the best life one can live, but we keep it to ourselves, c'mon. Honestly, we don't care one way or the other if God actually uses us.