muslims are anyway the first of the offshoots of christianity, i didn't count exactly but jesus and mary and the immaculate conception are mentioned at least 3 or 4 times

i don't know the exact details of the history but i strongly suspect that the "polytheism" that mohammed (and Gabriel) decry going on in medina were actually orthodox, as at the time i believe the catholic church was splitting and the eastern orthodox was forming and they, and the catholics both engage in idolatry