Reply #3: Like Stalin, Pol Pot, knew, the way to eliminate religious superstition was to kill religious people

[HamdenRice]

The examples you cite are of disturbed, perhaps sociopathic or psychopathic people. But people who don't have supernatural belief systems also do horrible things.

Stalin and Pol Pot each killed millions although they had no supernatural belief systems, and part of the killing was designed to rid the world of religious "superstitions."

The common factor is that the people involved are evil, not that they are subscribers to a belief system you disagree with.

As for your larger question: what can we accomplish without agreeing on an ultimate understanding of reality (I admit: I tweaked your statement a bit), I would say a lot.

What matters is our behavior and our consensus, not what we ultimately "believe". I remember South Africa in the 80s where atheist members of the South African Communist Party (maybe the best communist party in the world) and the South African Council of Churches, worked together like hand and glove.

What difference did it make that they had different perspectives on the "ultimate" moving forces of history?