Wouldn't Mohammed's version of Christianity be seen as a form of heresy? Also,does Mohammed in this timeline recognize Jesus as the son of God?A major difference between Islam and Christianity is that the Muslims believed that Jesus was a prophet,not the son of God.What are the other differences of this religion from mainstream Christianity?Surely,I can't imagine Patriarchs of the five cities would accept a religion that bans the consumption of alcohol,pork and tolerates polygamy.
I fully intend it to be a heresy, but hopefully one that will be accepted sooner or later as a Noble Heresy by the Romans.
Well the first requirement would yes be that Jesus was the Son of God - otherwise it isn't really Christianity. Mohammed would be probably a Prophet, or perhaps an Arab Messiah in the conquering sense, uniting the people under God.
I don't intend for the Patriarchs to accept the 6th immediately, if ever - perhaps the Nestorians, and maaaybe the Copts would back them in some sort of theological politics. Nestorians to have their own Patriarch, and if there are enough left, an Arian Patriarch. Not that any of these would be accepted by the core 5, but they may accept each other. In terms of kneeling, I mean that he acknowledges the Emperor as Vice Gerent of God, in a titular manner, but not in terms of any true temporal power. Just in an attempt to realpolitik the Romans into protecting the Arabs as fellow Christians, or at the very least not to persecute them if they travel within the Empire.
Problem is really the Trinity. Trinitarian views of Jesus are seen by Muslims as violating tawhid, absolute monotheism; Orthodox Christians aren't huge fans of non-Trinitarians, judging by their treatment of Arians. I really just don't see how you could get either side to compromise on this.
Let them have doctrinal differences, I don't really insist that the other 5 recognize the "Patriarch of Mecca", just that Mohammed has the balls to proclaim it, and to try and have it recognized. Hence "Contentious sixth".
Well, there were theories that early Islam was influenced by either Ebionitism or Arianism, which were both Unitarian Christian sects; both the Roman Catholic church and Eastern Orthodoxy regarded Unitarians as mere heretics.
Huzzah, there is hope! A fools hope. But hope nonetheless!
If he knelt to Heraclius, he would probably be toppled off by Arabs clans and never arise in a position of power in first place.
Non-Temporal, explicitly Non-Temporal. I'll have to update my first post to make this clear. I also intend to have him achieve power and dominance before he kneels, I'd only expect it to be triggered in advance if the Romans invade.