This is a false assumption. Literacy was more common among clergy, but that hardly make it a basic skill. Were you aware that it was not uncommon for monks that copied texts in the middle ages to be illiterate? Many of them were. Being a part of the clergy did not automatically mean you were literate. But let's assume the false assumption is true that literacy was a basic skill among clergy. The arguement still makes no sense. Most of the main figures in Judaism and Christianity were not members of the clergy. Abraham, Moses, and even Jesus himself. So why would God be limited to picking a man of the clergy for the Arabs but not for the Jews or Christians? And furthermore, much of Judaism was passed down strictly through oral tradition for generations. The Word of Jesus was not written down until after His death. Jesus spread His Word with only one mention of reading and one of writting in the whole New Testament. How does that make literacy a basic skill needed to teach the word of God? Oh, you mean like the polygamy of Abraham, Jacob, Solomon, and David? Yes, God did warn some of them about polygamy yet He still used them as conduits for his Word. And Exodus 21:10 sets forth rules for taking more than one wife. If God were limited to only picking perfect men (or women) then there probably wouldn't be any religious texts. What does that have to do with anything? But since you bring it up, the Bible is filled with arranged marriages (sometimes apparently of cousins even) where the husband was much older than the bride. And Christianity allows for freedom of speech? What about that commandment not to take God's name in vain? Is that free speech? Just because western society has moved past certain things that Christians say they believe in but refuse to practice doesn't mean you should expect the rest of the world to dump their religious convictions as well at the drop of a hat. Right, because we didn't have things like the Crusades, the Inquisition, the Salem withc trials. Yeah, Christians have a spotless record. I don't like Islam any more than I like Judaism or Christianity. I am an atheist, but I do believe that when people make arguments they should have some basis in logic and reality. I'm sorry that you don't.
sword can conquer land but not hearts and/or minds. If it was sword, then there won't be Islam right now, or at least, it won't be fast growing.