Why is it that Islam is called one of the worlds “great” religions? They are nothing but barbarians.
Because it has a lot of adherents, spread out over a large part of the world.
It's "great" in same sense that Hitler, Stalin, and Mao were among the "great men" of the 20th Century: Their actions significantly affected the course of world history.
Greatness can be good or evil.
“Why is it that Islam is called one of the worlds “great” religions? They are nothing but barbarians.”
Remember, Satan rules this world. So, to the “world”, it IS a great religion. One, rooted in evil...and without recompense. Clearer evidence is not needed.