The whole strategy of religions is to make the map of human interests as broad and vague as possible, so that everyone can find their excuse or niche or reason for existence in the canon of the religion they practice. If they couldn't, the religion wouldn't be very popular and it wouldn't last long. But the goal of a racket is to involve as many contributing actors as possible. This is why there is an "eye for an eye", but there also is "turn the other cheek". If you're a pacifist, you can find support, but you can too if you're interest in conquering or enslaving foreigners.
So yes, these crazy people find various evidence of religious support in Christianity because that is what Christianity - and most other large, organized religions - are designed to do.