Are you aware of the Arian Heresy?
Muhammad starts to take Advantage, during the Decline of the Roman Empire under Heraclion. In order to have a plausible start he proclaimed loudly that those contentions of the Arian’s, Catholics and Jews had brought on the disasters of the Roman Empire.
Then under the counsel of an Arian monk called Sergius and some Jews, he wrote up a harmony of the Catholic, Arian and Jewish doctrine which he called the Koran.
And in order that there might be and end of the contentions, he ordered that fire and the sword be sought against those who rejected that Compromise.
And thus Arius gave occasion for the blasphemous reign of Mohammad, in which the Son of God is subjected every day even now to insult.
From Loci Theologici by Martin Chemnitz.