Although marxist atheists think they are intellectually superior to Christian believers they merely replaced their authority of God with Government. Every criticism they have of God you can replace the word Government and the same criticism would be equally valid. For example: God kills then says thou shall not kill. Well the government does the same damn thing.
Marxists bow to the altar of Marxism and believe in the higher power of government.
Christians bow before Jesus and believe in the higher power of God.
Both have replaced their own mind and thoughts with an ideology or belief.
Here's the difference:
Christians almost exclusively don't get their morality from the Bible. Sometimes they'll be a little motivated to do the Jesus "turn the other cheek" or give to charity thing. Pretty much everything else they'd learn from the Bible is horrible though, so they're wise to ignore that, and they typically do.
Marxists at least follow a modern theory...which is obviously a way better source for ethics than most of the Bible. That said, given how horrid a source for ethics most of the Bible (apart from the New Testament) is, that's not saying much. I think LaVeyan Satanism is pretty clearly a better source for ethics than most of the Bible, and they encourage vengeance.
So, on the one hand you've got people who follow the modern theory called Marxism, which may or may not be wise...but it's rooted in reality.
On the other hand you've got people with a vastly worse code of ethics, which they ignore for the most part so as to (wisely) make up their own.
If you've got a problem with Marxism...fine...I think the solution is to talk about its specific weaknesses though. I don't think it has much in common with religion though or God-belief. Religion's big problem is that (at least in my view, it's false). It sends people down paths in life that are less-than-ideal paths to go down (if it's false) because they have an incorrect view of reality. Marxism is rooted in reality though...and if I thought God-belief were rooted in reality, I'd feel the need to argue the specific pros and cons of following that belief system just like I'd want the specific pros and cons of Marxism discussed.
I haven't looked much into Marxism though...but we do need laws or chaos will result. We don't need laws from the Ten Commandments. Without the Ten Commandments, our code of conduct would be just fine.
Just to point out, there IS a higher power. For each of us, for ALL of us individually, there IS a higher power. For governments, there IS a higher power: those who are insufferably poorly governed. The entire human species exists under a higher power: reality.
What kind of arrogance believes they know everything, so they can conclude that there is no God? While numbers don’t prove anything, atheists are in a minority in the population, and are not a highly intelligent demographic. Of the most intelligent people on the planet, roughly 2/3 believe in God. Even the most intelligent can’t tell you if our Universe is a special case, what was there before time and space, and whether or not our Universe is part of one or more other Universes beyond our ability to detect. IMO those who are not open to the possibility of God, but have the opinion say, that aliens have been on Earth, are just silly and have an inflated view of their gifts.