Their religion calls for mass slaughter of "infidels" while they are could also technically pass as christians, since their holy book mentions Jesus as the son of god.

Not really. The only militancy you'll find in Islamic theology is defensive. There is a militant component to "jihad" but it is simply religious self-defense in line with the spirit of the second amendment and this too compromises a tiny portion of what "jihad" is, jihad is just any religious struggle against evil. The most significant religious struggle is the battle against your ego. This is not me saying it, it is straight from the mouth of Muhammad according to Bukhari. Our own egos, as individuals and groups, lead us to the greatest of all evils and that is why "jihad-al-nafs" or a religious struggle against your ego or self is the primary focus of jihad. When I come on here to explain why I am a Muslim despite any potential animosity, that to me is a great religious struggle which historically falls under the banner of jihad. I say all this just to illustrate that jihad is not malicious to me and it doesn't cause me to go out and kill "infidels". I'll concede to this much, there is a militant component to jihad, I can't deny that. However, you should do some deeper research and realize that even the most deluded, militant so called "jihadi" has to create a narrative of defensive warfare to give any theological credibility to their rhetoric