I’m not arguing any stance you may have, I was giving the OP a reason why Islam and Christiany have several similar aspects. I’m not saying Mohamed derived his point of view from his polytheism. He was in the middle of a culture that was saturated by it through no fault of his own. It’s just how things were at the time of his early life. He simply was tired of the polytheistic religions that surrounded him. That is what I meant by “as a response”. He was trying to get away from that and find the One God that Judaism and Christianity professed. Just like there were polytheistic people who arrived at Mecca during this time for trading purposes, Christians and Jewish people arrived as well. Mohamed was attracted to the religions, but did not fully agree with them. I’m not sure if what you are arguing in that last sentence is a statement questioning the concept of The Trinity, but if it is, ( now I’m not sure what religion you are) we as Christians ( for the most part) profess One God in three distinct persons. They are not like three different parts of a God, that is to say, they aren’t like completeting a God by each adding something. They are one substance all the while being different persons. It’s a mystery of Our Faith that can never really be understood. Again, take out any history book, Mohamed lived a time when Mecca was a trading post. It was a booming city that linked the Mediterranean with South Arabia, East Africa, and South Asia. The Kabba, whose first construction dates back to the 5th century by the Quraysh tribe, originally was a place where these traders from different places in the world left offerings to their Gods ( especially Hubal, who was at the time Mecca’s most important pagan deity). Mohamed stumbled upon Christianity and Judaism because of trade.Though he liked and kept several key aspects from both religions, he didn’t fully agree with either one and came up with his own doctrine based off of the ideas that he he accepted for both Christianity and Judaism. This is why there are many parallels. Grant it, the differences are crucial and are the reason why the church rejected Mohamed’s visions and revelations. They were false. Now am Insaying he made them up? Not necessarily, without meaning any disrespect to our Muslim brothers and sisters, there may even be a psychological explanation behind them. Obviously, we’ll never know. As to polytheism and monotheism, the main difference between the two is that though, as you say polytheism would simply embrace any new deity presented to it ( for the most part), Monotheism holds its one daity to be the only one and true deity. Mecca boomed as a trading post precisely because of its polytheistic views. It embraced every God that arrived to it. However, Monotheism condemns the recognition of any deity outside of its own.