Jesus told us to be peacemakers, to turn the other cheek and to love and care for even those who do harm. The members of the early church took those precepts to mean to avoid harming another person in any circumstances. They believed it was spiritually better to die than to kill another person.
The early Christians were very courageous in following Jesus precepts. I have found very few modern Christians who are that courageous. Most modern Christians deny Jesus' precepts.