O People of the Book! Commit no excesses in your religion: Nor say of Allah aught but the truth. Christ Jesus the son of Mary was (no more than) a messenger of Allah, and His Word, which He bestowed on Mary, and a Spirit proceeding from Him: so believe in Allah and His messengers. Say not "Three (Trinity)" : desist: it will be better for you: for Allah is One God. Glory be to Him: (far exalted is He) above having a son. To Him belong all things in the heavens and on earth. And enough is Allah as a Disposer of affairs.
In the very same lines the word of god and spirit of god are buried within things not to believe in.
I shown this to a group of Muslims they just laughed at me but would not refute it. Two people kept repeating that he was a messenger of god. Yes, I said he came down as a humbled messenger but was god himself.
The Koran is a deeply self-contradictory book, a pastiche f truth and error. He picked up lots of things in his caravan raids --- money and women and herds and fragments of the doctrines of different religions -- he picked up spiritual concepts like Velcro picks up lint.
He was no theologian. He was a religious charlatan: a warlord who knew how to use what he picked up.