The term “Allah” existed long before Mohammed and Muslims were born.
Mohammed just hijacked the word and attributed characteristics to it out of his own head. I think the Muslims have made up some 95 names for their god since then.
While some though not all Muslims believe death in jihad is a way to guarantee a place in the garden of pleasures that is their heaven, in one case in their scriptures a man achieved heaven by simply giving water to a dog.
They also use the Arabic word for lord - rabb- to refer to their god.
Interestingly, while they deny the three persons of the godhead, in the Quran their god refers to himself in the plural “We,” etc.
In another pat of the Quran they are actually told to refer their questions on faith to the people of the book. That’s a weird one that a few clerics have done some contortions to explain away.
The Quran wasn’t written like the Jewish books or the NT... throughout Mohammed’s life his followers did not think to write anything down in a serious way, relying instead on just asking him directly and listening to his pronouncements. He dictated what he said were Gabriel’s words to him and someone would write it down on anything handy, from a flat rock to a palm leaf to skins or bones. The most devoted followers would memorize this and then toss the stones or leaves aside because they no longer needed them. This continued until a battle occurred and a large number of the men who had known all Mohammed’s Gabriel quotes by heart were killed, leaving very few if any who had memorized everything. What if all of those who knew the words by heart should be killed?
Someone thought that was a problem, so they decided to gather up every scrap and object they could from all across the realm and make sure it was copied down.
This is why the Koran is a disordered mishmash , other than they tried to put the longest passages in the front right after the short statement of faith, followed by shorter and shorter passages to the end, which means you can find passages Mo cranked out late in his life in front of ones from early on with no rhyme or reason.
But here’s a kicker... when they gathered the bits that people bothered to write down and copied them, they destroyed the original bits. So there is nothing to go back and fact check or to study anew should some information be found that might change the contextual meaning. Where Judeo-Christian practice is to keep texts and compare them, giving more weight to those written closer to the times they describe, etc., in Islam it is just the opposite. Recent revelations outweigh or abrogate older ones, etc.
Older passages in the Quran tend to be more open-minded towards other religions but more recent passages tend more to hostility towards the other two faiths, probably reflecting Mohammed’s impatience and growing frustration with people of other faiths not seeing things his way.
I've read that "Allah" is nothing more than the Arabic word for "God" and that Arabic speaking Christians routinely use that word as well.