Communism if nothing else is a collectivist mentality and its temporal salvation comes from acceptance by the group and immersion into it. Communism claims that Christianity is an opiate which enslaves which, of course, is contrary to the reality. Communism offers the siren of equality but delivers enslavement.
Islam is cultist and utterly subordinates the individual to the cult. Small wonder Communism is so comfortable in its presence.
That’s an excellent analysis and it really makes clear how the two differ (in a way that I think most people don’t understand).