We all know that Islam is a monotheistic religion condemning idol worship/polytheism by calling it the greatest of all sins . But what about henotheism? In henotheism, God is one with multiple demigods/deities (like Angel Gabriel and jinns). Is believing in henotheism also a sin?
The following are the Islamic beliefs about God:
لا إله إلا الله
There is no god, except Allah 47:19
Allah is One112:1
وحده لا شريك له
لا حول ولا قوة إلا بالله
ان كل من في السماوات والارض الا اتي الرحمـن عبدا
There is no one in the heavens and earth but that he comes to the Most Merciful as a servant.19:93
انني انا الله لا الـه الا انا فاعبدني واقم الصلاة لذكري
Indeed, I am Allah . There is no deity except Me, so worship Me and establish prayer for My remembrance. 20:14
Any belief that contradict the above is called shirk and is the greatest sin4:116. Henotheism is the worship of one God, without rejecting the existence of others and this is shirk as well.