Islam is much more problematic than it seems. First 1Jn2-22 does not apply to them, since HE IS the messiah (witch doesn't imply his divinity for them) even for them.
On an other side, the only fact Avicenna and Averroes have been that much discussed by the medieval theologians shows what they think isn't that stupid (even though it is mainly about commenting and interpreting Aristotle). The problem is about encounter with modernity. Actual Islam is, and sounds stupid, as much as modernist Christianity does. They have great theologians Ibn Arabi, Ghazzali, Mulla Sadra.
The real problem is the following : How can a man, who sincerely dedicates his life to a God, who is metaphysically VALID, can worship the devil ? With ZERO evidence of it, except a bunch of faggots with a clown pope.
Don't get me wrong, Christianity (apostolic one, not the fake ones) is the deepest revelation of all, yet, Gn9.9-9.17 and Jn10-16 points to the fact that you can not limit the Logos and his mercy.
tldr : Traditional muslims have good metaphysics, metaphysics hardly lead to the devil, cf Aristotle. Actual Muslims are retarded because, like protestants, they negate tradition and are in a Sola scriptura approach.