And your point is... Christians haven't lived by Old Testament rules in 2,000 years, although in the earlier years of the Church they did spill quite a bit of blood. But they at least have the decency to admit it.
The Old Testament did command Hebrews to do some pretty brutal stuff, but, hm, that was, what, 4,000 years ago?
The Buddhists were violent in the distant past, but today are almost UNIVERSALLY known for their peaceful, gentle manners, the exception being in Myanmar (Burma), where they are brutalising the Rohingya Muslim people, although that fight is more about ethnicity than it is about religion.
The point I am making is that Islam has ALWAYS been viciously violent, and remains so to this day. Although it is true to say that not ALL Muslims are terrorists, it is ALSO true to say that the VAST majority of terrorists in the world ARE Muslim.
Let's put it this way. Jews living with Christians, 21st Century: few problems. Jews with Hindus, no problems. Jews with Buddhists, no problems, Jews with atheists, few problems. Christians with Hindus, Buddhists, or atheists,few or no problems. Etc, etc.
Muslims living with Jews: Problems. Muslims living with Christians: Problems. Muslims living with Hindus, Buddhists, or atheists: Problems. MUSLIMS LIVING WITH MUSLIMS: HUGE PROBLEMS!
So, you tell me... should civilised people be concerned or not?
I have to log off for now, but there you are.