I look at the term “human” as more of a condition or maybe a status. Are the jihadists human? They are beings, homosapiens, men (well, sort of). But how much humanity is there in them? I would say, not much.
What kind of people can claim to be human and yet behead others with dull knives? How about those who stone a helpless woman to death for enjoying the company of a man to whom she is not related? Or killing thousands of innocent people in a skyscraper just to make some kind of point?
Human? It’s a stretch.
Mankind was created in the image and likeness of God. Through sin, human nature is fallen, diseased, and corrupted. Read the Book of Genesis ... it's very informative on the matter. Purely by the Grace of God, some folks rise above that corruptedness, some can become extraordinarily saintly. The Image of God shines quite brightly in them. Others reject God's Grace, reject being the Image of God, and truly wallow in their sins. There seems to be no depth of depravity unplumbed by such folk ... and yet it seems daily they come up with new ways of being hideous.
Human? Precisely. Human, fallen away from God and given over to evil. You think you have no tendencies in that direction yourself? Think again. We all do. Repent! Turn yourself over to Christ. He is the way, and the truth, and the life ... and the truth, HIS truth will make you free.
Mohammedanism represents a radical turning away from Christ, a radical rejection of His truth and life. It sets up a falsehood in His place. Socialism, incicentally, does likewise. The last 100 years illustrate the abject horror of which men are capable, when they turn to mohammedanism or socialism instead of turning to The Lord.
That's probably more answer than you wanted. I hope it's helpful.