I'm really thinking of Christian sanctioned warfare or an execution perhaps.
Obviously there's lots of sancioned warfare and executions in the old testament.
Jesus we are often told is the ultimate role model.
I'm not aware that he killed anybody, I can't imagine him fighting in the Roman army if conscripted and he actively prevented an execution (let he who is without sin cast the first stone etc.)
So I'm interested in when that changed and whether it was Constantine hijacking Christianity or whether it changed in the early church before that.