With Communism it is the Party, using the state as enforcer, and the belief, or at least the pretend-belief, in the perfectibility of man.
With Islam it is Allah through Mohammad, the anti-Christ. It is their way or the highway (of death or servitude).
With Judaism it is God. Judaism and Islam have a lot in common with the key divergence being the nature and goals of their prophets.
Christianity is the continuation of Judaism with a new mandate which gives man a personal conduit to God through Jesus. Christianity is also distinct in that it puts emphasis on the individual rather than a group. That is one reason it is so compatible with our form of government.
Both Communism and Islamism are anti-Christ, anti-Jew, and anti-individual freedom. That is why they work so well together in subduing others. Unfortunately for them, in the end, neither will be tolerant of the other.
All of this is the classic battle between good and evil. One need only to look at which sides rely on deceit and force and who depends of love and sharing to know which side to be on for long term happiness and success.
As has always been the case, it is evils role to disguise itself as good and confuse its victims. We are only discussing methods here.
Just so. This is the Biblical view. And that view is "right on" at all levels.
In the end we know who wins. In the interim, the situation remains murky for us as individuals and as a culture - which is rapidly being driven post-Christian, just like the Europeans.