Just to add further clarification, "Allah" is Arabic for "Yahweh" - the God of Abraham, Isaac, and Jacob, and God the Father of the Christian Trinity.
I've noticed several references to Allah in this thread, but I think a key fact has been missed.
Both the Bible and the Koran define the 'god' to which they refer. Those definitions form what we know of those beings, and point to two different entities. Essentially, Allah, as defined by the Koran, is not the same being as is God/Yahweh/Elohim/etc as defined in the Bible. I think the main reason that the Masonic phrase "GAOTU" was adopted was to paper over such differing definitions in the interest of harmony.
Context and intent determine the proper understanding of 'Allah.' When a Christian uses 'Allah' to refer to the God of the Bible in his Arabic prayers, he is on proper linguistic and religious grounds. But he does not mean the Allah of the Koran when he does so. When a English-speaking Christian uses 'Allah' in the Shrine initiation, for example, he is referring to the god of the Koran, not the God of the Bible.
Such 'conflicts' occur elsewhere. The Muslim, Mormon and Christian may all pray to 'Jesus,' but they are, in fact, praying to three different entities, as each has defined the term differently. In religion, as in all other topics, we have to use common defintions to communicate effectively.
So, 'Allah' is indeed the Arabic for 'Yahweh,' but only under certain conditions. It is a mistake to assume that they are different names for the same God. Cordially, Skip.