It is a complicated question with a complex answer that varies between many different groups and individuals.
Most communist are atheist or follow the slogan that "Religion is the opium of the masses." But as Maoist we are taught that;
"To link oneself with the masses, one must act in accordance with the needs and wishes of the masses. All work done for the masses must start from their needs and not from the desire of any individual, however well-intentioned. It often happens that objectively the masses need a certain change, but subjectively they are not yet conscious of the need, not yet willing or determined to make the change. In such cases, we should wait patiently. We should not make the change until, through our work, most of the masses have become conscious of the need and are willing and determined to carry it out. Otherwise we shall isolate ourselves from the masses. Unless they are conscious and willing, any kind of work that requires their participation will turn out to be a mere formality and will fail.... There are two principles here: one is the actual needs of the masses rather than what we fancy they need, and the other is the wishes of the masses, who must make up their own minds instead of our making up their minds for them" (1)
The first four sentences of this quote spell out exactly what a communist stance should be towards the banning of religion. Especially in the USA it would be impossible to expect the proletariat to allow a revolutionary government to ban their religion. Religion is important to the proletariat. And to ban it would be to go against the wishes of the masses. It is also important to point out that some nations with strong religious roots have turned to communism our socialism.
It is an error to call for the banning of religion in a nation as a whole. It shows people who espouse this would run the nation as the few ruling over the masses. But I would never suggest that we ban religion as a whole.
But it can also go both ways. As a comrade of mine said "right wing deviations should be banned" I think watched and monitored would be the best at first followed by state criticism and propaganda against right wing deviations of religions. Then when the masses are ready and support it we can close down the right wing deviations of religions. The other side of the coin is that some religions and certain sects of different religions are left wing in nature. They would support a revolutionary government that is centered around empowering the masses over the few. They would support a government that puts needs above profits and material want.
Religion will only be our complete enemy if we constantly attack it and threaten to ban it. Not all sects will oppose a revolutionary state. Some sects should even be reached out to and brought into the communist and socialist circles. Many of sects espouse social justice at their services. Should we alienate these people because of a quote by Marx? NO! It is foolish how communist act towards the religious peoples when we need to be engaging them.
Written by; Dustin Slagle
1, Quotations from chairman Mao, the Mass line. Taken from Marxist.org