A distinction without a difference.
All religions are ideologies.
Ideology: the body of doctrine, myth, belief, etc., that guides an individual, social movement, institution, class, or large group.
Religions are a subset of ideologies.
The idea that Islam is not a religion is based on the Christian idea of “Give unto Caesar,” implying a separation between religion and the rest of life.
Islam does not recognize that separation. It is a complete way of life.
It’s entirely accurate to say that it’s more than a religion, by western civ definitions. But it’s not accurate to say that because it incorporates aspects that we don’t normally consider religious it ceases to be a religion.
Islam isn’t a guide it’s specific instructions that must be followed to the letter. This makes it a social order which is political in nature. It’s not like any other religion or ideology on the planet. Not even similar.
More technically, religion is the method of worshiping God.
While it is possible to remain in fellowship while practicing a religion, many fall out of fellowship by placing a religion before God.
The Adversary seeks for others to worship him as a substitute for God, so their are many false religions, such as Islam.
It isn’t sinful to be religious, but many who are religious, never have fellowship with God. Religion to those people becomes a counterfeit substitute for that relationship.