Yes, Abraham was a worshipper of God, our Yahweh, even among the pagans in the land of Ur. I am not debating if ever there were Yahweh worshiippers other than the Jews, I AM, however saying Muhammed most certainly counterfeited Allah after the monotheisms of the Jews and Christians. Yes, at some point after leaving Abraham even Ishmael and Hagar I'm sure worshipped the God of Abraham, but it became bastardized many years later and culminated with the hoax of Muhammed and his "holy book". Muhammed's god is not the God of Abraham, Isaac and Jacob. If he is, he is extremely schizophrenic. Just because a deity is called a deity in another language doesn't make two distinctly different deities equivalent.