Religion is certainly serious business from the doctrinaire frame of mind. From an outsider's standpoint, religious behaviour is intrinsically silly. Mystics and those who belong to the esoteric traditions tend to appreciate that silliness because their practices contrast with the superficiality of the masses' understanding of their scriptures and rituals.
But my point isn't that all religions are full of comedy. I've written a series of articles on how Judaism is implicitly satirical. Judaism emerged as a moralistic takedown of polytheism. Yahweh is the ultimate tyrant who makes the pettiness of polytheistic gods more obvious by comparison.
Christianity carries on the implicit satire, with its story of God's being killed by his creatures, but Christians lose their sense of humour about their religion, by accommodating Roman polytheism via their syncretism and alliance with the Roman Empire.
By the time we get to Islam, the satirical force of Judaism is lost, and the practice of Islam is strictly business, as you seem to appreciate.
Frivolous humour might be needlessly insulting, but Jewish satire was hardly frivolous. Polytheistic theocracy was the predominant form of human tyranny in the ancient world. Jews were implicitly satirizing the oppressive empires of their day, the empires that came and went, conquering peoples and boasting about the might of their gods.
