I'm not talking about the rulebook everyone reinterprets every century. I'm talking about the actual culture of Christianity. I said American Christianity specifically.
I'm sure the people behind the inquisitions, witch burning, crusades all cared a lot about Matthew 5:39-42 (very few were literate anyway)
People seem to have trouble understanding that the Christianity of today (doesn't matter if it's Evangelical, Reformed, Orthodox, Fundamentalist, et. al.); the Christianity of today would indistinguishable from the Christianity of 200 AD.