Start reading through the Old Testament and see what the prescriptions are for adultery. Christians who believe in the Bible don't support that. I'm not convinced that all Moslems follow the strict interpretations of the Koran either. I do believe that the case could be made for the arguement that both promote violence, if their words were enforced rigidly.
I know what you're talking about. I wish I had a better answer for you.
The problem with that equivalency argument which one can make about unpleasantries in the Koran, Old Covenant, and the Talmud amongst other books of religious laws and "words of God and prophets" is that currently it seems to be only the Muslims who are indeed foolowing these unpleasant edicts and using them to justify their actions against non-believers or infidels...at least to any great extent. Support for action against Israel, Jews, as well as Christians and Hindus is widespread in the Muslim world. There is no such equivalency whatsoever in the "Infidel" world except perhaps from Hindus in the conflict areas of India and I have not heard that they are using Hindu teology to justify their dispute with the Muslim extremists in Punjab and elsewhere.
This battle has been going on for over a millenuium now...the Infidels are fluid and do change proxies and whatnot but the Islamist side is rather static. Turkey being a big exception....but their fight was more pure hegemony than Islamic hegemony at least during the last Ottomans.