Arabia at the time of Mohammed was home to countless religions and his home city, Mecca, was a pilgrimage center for most of them. The city was a pantheopolis with dozens of temples and shrines of various pagan flavors. It was that city's chief "industry", tourist draw, and big business, which Mohammed began to disrupt when he started preaching that they were all wrong and that there was really only one God.
It's certain that he acquired that idea from Jews living in Mecca and from them he also gained a very distorted version of the Torah. From local Christians he likewise heard of Jesus. By twisting the stories we know from the Bible (all decidedly committed to parchment and papyrus by the 600's AD) he preached and preached until the city fathers had had enough and plotted to kill him. He escaped to the nearby city of Medina where he continued to preach and gather together a military force to go back and take Mecca.
Thus, he went from an interested observer of Judaism and Christianity, to a wannabe new prophet of "The God" (what the word "Allah" literally means in Arabic), to refugee, to warlord. In the last pose he had entire villages and towns destroyed, the men massacred and the women and children enslaved. The Arabs, being a warlike tribe to begin with, converted en masse and became for a hundred years an all conquering army sweeping though everything from Persia through Egypt to the Pyrenees, always and till now converting by extortion and the edge of a sword.
Thanks, I have one more question, if you please:
In 1983 while studying the ME, I was taught that all 3 “great religions” believed in the God of Abraham. Issac and Israel.
Now I think that allah, is not another name for the God of Abraham. Could allah be another name for a false god called baal? I thought baal was a pretty big deal in Egypt and in the Arab world.
Couldn’t we solve this debate by asking: do you beleive in the God of Abraham?