First, most societies seem to believe they maintain peace through threat of violence. Throwing someone in jail is a form of violence. Monotheistic religions threaten the same with eternal torture in hell or similar, I can't imagine a more plain form of physical violence than that!

However, the second reason this doesn't make sense to me is that in both cases this is wrong, society really maintains decorum and peace through social pressure and inherent human distaste of violence and unfairness, which may be baked into our shared psychology. Religion builds on top of this, but it's not due to the 10 commandments that people don't murder - people generally just don't want to murder, and those that murder anyway aren't stopped by knowledge of, or even faith in, the 10 commandments (they may do it in a moment of passion). Same for law - seems people just do what they feel is right, or if wrong, what they think they can get away with. Hence why severity of punishment doesn't positively correlate with reduction in crime, but likelihood of getting caught strongly correlates.

So thus my third reason: Organized religion exists to convince people to behave in opposition to their nature, against those indefinite somethings that make them feel uncomfortable with harming others. They make rules that make them do things that are odd, bizarre, or unethical, such as isolating themselves from their friends, family, and neighbors, or giving a lot of their money away to the religion. Historically, they make them go kill a lot of people from other religions, despite these people being of the same class as them and having the same problems back home (similar to how State authorities, such as Kings, did, or in the modern era, Capitalists). Without organized religion leveraging massive capital and organized labor to convince people to act against their nature, I imagine our history would have had a lot less suffering!

As for your criticism of what I take to be either Maoism or Stalinism, as it seems you're speaking of the USSR or the PRC as a single entity, I feel that's more just a criticism of authoritarianism in general that I basically agree with. Fascist states as well don't recognize people, hence why even supporters of fascism often find themselves, to their great surprise, on the wrong side of a firing line that they had supported being pointed previously at their neighbors. All to serve the State. To a far lesser extent I think liberal democracies suffer from this as well, see for example the USA's extensive interventionist activity post WWII to maintain its hegemony.

I accuse capitalism of the same thing you accuse totalitarianism of - all things, even religion, are ablated down to something marketable. Just take for example the holiday celebrating the birth of Christians' founding prophet: transformed into Coca Cola's gleeful, uninhibited, consumerist orgy - especially ironic since the prophet Jesus was by all accounts a communist! "It is easier for a camel to pass through the eye of a needle than a rich man into heaven," or recall his violent expulsion of bankers and salesmen from the temple, or his lesson of the post-scarcity nature of our world and how this should be leveraged to freely give food to all (the "miraculous" creation of infinite fish and bread, a clear metaphor for the endless bounty of the Earth).