Logically, most “Christian” violence can be dealt with fairly easily by noting that the perpetrators were failing to live up to the tenets of their own faith. The prescription for this is better faith, not less faith.
A harder issue, and one which has come up for me recently in discussions with fellow Christians, is the violence that appears to be sanctioned in the Old Testament.
We have addressed this in our Q and A section: “Christians believe that God is good, and yet why did God order the slaughter of all Canaanites? Isn’t that a contradiction? Isn’t killing the Canaanites a violation of God’s own Law in the Ten Commandments?”