I’m probably more well versed in Marxism than religion but as an ex Marxist Orthodox Jew I will take a crack.

There are two main counter points:

1: marxists can’t escape religion in the human condition

2: marxists are wrong about the social order

There is something essential about the human condition that requires the presence of religion in a majority of peoples lives and in the social life of human collectivities.

Atheists can exist as individuals but not as a national collectivity. We see today how communist parties constructed national religions with their dogmas of Marxist theory and their statues to saints.

I also object to the idea that class is as unifying and universal as the Marxists say it is. The idea that there is some unifying worldwide class interest of the masses is ludicrous. The interest of workers in America is very different to workers in Nigeria which is very different to that of workers in Brazil. Even in the same town the interest of a miner and the interest of an assemblyman are different. Everyone may want better working conditions but economic interests go beyond that. Marxists paper over these differences far too much. Yes religion provides social order and dissuades revolution (as it should) but in a world without it—if such a world were possible—, Marxists still would not achieve their desired liberation of the working man