mohammed also had Gabriel tell him over and over again to admonish people to not form sects and that all who follow the Law are muslim, this one thing specifically is a big innovation from the christian situation

the catholics did their unum sanctum and presumed to dominate europe with their religion and in the process polluted christianity with all this pagan doctrines about the sun god

i'm pretty sure there is several statements from Jesus to the effect that the earthly Church has no business making doctrines