To which he'll probably reply: "Which Bible? The Catholic Bible? The King James version? The version used by the LDS Church? How about that smarmy, New-Age, PC Bible that came out a few years back?"
To which I would reply- The New Testament- or some translation of it. None of which tells us to murder and behead those non Christians in God's name.
Then ask him where Islam's 'New Testament' is- the one telling their followers to give up the old, brutal ways?
If they don't follow- and don't believe in- those passages- why not revise the Koran?