"Religion is the sigh of the oppressed creature, the heart of a heartless world, and the soul of soulless conditions. It is the opium of the people."... Karl MarxI've generally agreed with Marx. Religion allows people to accept a lot of shit but also can motivate change in positive and negative ways.
One of the benefits of and rationale for most religions is the idea that things don't end when you die. That some higher force allows for a future in some manner. Or that the higher force makes life worth living. Things will be taken care of. The future even when you are gone has some guiding hand.
Religion seems to be part and parcel of humanity since it arose in every single society throughout history. I imagine religion began at the point of human consciousness where they began to look up at the sky and wonder what the hell it all means. There is a 100% chance you will die and belief in a higher order keeps you somewhat optimistic.
But where does that leave you if you are an atheist knowing full well that when you die, worms will be eating your brain?
Not all atheists are socialists and not all socialists are atheists.
Not all socialists are Marxists but all Marxists are socialists.
For the latter group, Marxism is a form of religion. Socialists are often the most optimistic people I know. Their belief that a better society will ensue is similar to evangelicals who are waiting for the rapture. Except socialists believe they will be the ones to make their rapture come true, not wait for a higher power to do so. But I also find that many have their own higher power by following some leader or ideologue.
The essence of Marxism is a dialetical/scientific analysis of the movements in society through history with the inevitable fall of capitalism and the rise of socialism/communism to replace it. What has so far gone wrong in the prediction is how the socialist states which replaced capitalism morphed into not a dictatorship of the proletariat but a dictatorship usually dominated by one strong voice (Stalin, Castro, Kim) or an oligarchy of sorts.
A good friend of mine and mentor, a lifelong independent socialist with a degree in Marxist economics has come to the conclusion that the Marxist assumed there was no such thing as human nature - the need of some to dominate and control. I tend to agree. Socialists believe that people can be molded into something better. They believe this with a religious fervor.
Trotskyists have an answer by fundamentally claiming that all these examples are failed socialist states and that the true revolution has not taken place yet. And besides, their version of socialism requires that it exist worldwide - thus they are internationalists. They believe the states that call themselves socialist have been forced to morph into some forms of capitalism due to the fact that most of the world is still capitalist but that one day that will end.
Can capitalism morph into socialism peacefully? Some socialists believe it can - democratic socialists for instance.
But the class that calls itself revolutionary socialists recognize that capitalism won't yield without a massive struggle and it will turn violent. I tend to agree even though I am not a revolutionary socialist. I tend to think that it is more likely that the masses that are expected to make a revolution will more likely be suppressed or manipulated into supporting fascism rather than socialism, as happened in Germany when the Nazis and socialists clashed.
Optimistic socialists believe it was errors on the part of the socialists not the forces of history that led to that outcome. I'm not an optimist. I see doom and believe the best we can do is rally enough people to win concessions to modify capitalism, like FDR - which is where the Bernie/AOC crowd comes from -- social democrats. The reality is that to get to that point took a massive depression.
Lenin's contribution was the idea of a vanguard party of people with advanced ideas to lead the masses into socialism. These parties are supposedly democratic and operate under democratic centralism where majority rules and everyone else goes along. But in reality, one or an oligarchy of voices exert major influence and end up dominating.
Thus many socialists who believe in the vanguard party call themselves Marxist-Leninists. There are Marxists who are not Leninists.
Membership in these vanguard parties is essentially akin to belonging to a church - a religious experience where the party is the most important thing and subsumes all else -- loyalty to and building the party. We saw this inside MORE with the ISO crowd. And look at the outcome.
My experience in MORE taught me a lot about socialists in vanguard parties like ISO and how they operate. One thing I always noted that nothing ever goes wrong for them - that no matter what you must put a happy face on it so as not to discourage people. As an example after 3 months of silence after the UFT election disaster, they finally figured out how to try to sell it as a positive which they posted on their web site. It was an LOL moment.
People like Mike and me who were critical of MORE internally came under attack for pointing out reality and calling for analysis that would lead to fixing things that weren't working. They didn't want to hear that - criticism was negativity. No analysis was needed. After all, they were operating under a higher power that existed outside the organization - they were the true enlightened and knew what was best. Thus you see organizations like MORE aim to convert the masses to their ideas rather than let the issues the masses are concerned with take precedence. An example is that no matter what is going on in the schools, MORE will push its agenda, not that of concern to UFT members. (Prediction for this year - the contract and Black Lives Matter week plus one other issue to keep people busy for the next school year. And then brag about how successful the work was.)
Of course ISO fell apart but even the ISO people I talked too said the same thing - what a great experience it was, no regrets and how the future still looked bright. They has been spending upwards of $5000 a year towards ISO - tithing of sorts - and it was all worth it. OK. That they all seem to use almost the exact same words is evidence of the religious aspect of these leftists - almost as if they were reading from the bible.
Now everyone piles into DSA which is holding a national convention in two weeks and some skirmishes and wars will break out in that big tent organization. But no matter what the word going out with religious fervor will be optimistic.