Second you ignored my comment about the personality cult. Those are functionally identical to religion and anyone not worshipping the word of Mao did not fare terribly well during the cultural revolution or the great leap forward. It's the blind unthinking worship which is the problem wither of a god or a cult leader.
In my opinion nationalism is the most dangerous form of fanaticism. It pulls in both atheistic and religious people in equal numbers. The brainwashing starts early in childhood. People are taught "us vs them" and will happily offer their lives for the cause. Religion has caused many wars but they couldn't fill their armies without nationalism blinding both sides. It's really a cancer.