Islamic Arabs have told me that they believe Allah is the God of Abraham. The word “Allah” is just the Arabic word for “God”. The Arabs believe they descended from Hagar and Ishmael, while the Jews descended from Sarah and Isaac. The father of both men was Abraham. They believe Hagar was an Egyptian who was a slave of Abraham.
They are descended from Hagar and Ishmael, and are - in fact - half-brothers of the Jews. The God of Abraham, however, came to this world as a child, born of a virgin, and was crucified for us all - Gentile and Jew. Islam rejects this in the strongest possible terms, as was shown to Appy from his authority on Islam, the Koran itself (see post #27, above.)
Simply because someone is biologically related to someone else does not in any way mean that they necessarily will worship the same God, and - in fact - this is what has happened to Semites (among others) who worship "Allah." "Allah" is just another name for Ba'al, Dagon, Nimrod, and a host of other "false gods" that cropped up in that part of the world. The fact that so many believe the lie that is Islam does not make it true.
Islam had and still has it's beautiful aspects, and very ugly aspects.
It was a thriving, liberal, progressive religion in the middle ages, but has degenerated to a leaderless, variegated religion, with dozens of different interpetations, including some very bizarre and violent interpetations that we hear about now.