Well, do them a favor and ask them how many people have died at the hands of a Muslim god.
See what they have to say.
C.O'D.
Actually, all three religions based on the old testament have caused humanity a lot of grief, but specially Islam and Christianity. Contrast that to Buddhism - not a single war since Ashoka in 500 BC (and Buddhism is about 600 years older than Christianity).
The problem is that any religion that says "my way is the only way" will lead to conflict. Somewhat ironic that Islam and Christianity are now headed to a terminal showdown.