Who killed more people Atheists or Christians?

[Anomalocaris]

I don't possess your certainty that he was 'as atheist as they come'.

Whatever else Mao was he was a not inconsiderable poet, prose writer, and skilled wordsmith, and was adept at using both classical chinese literary allusions and devices, as well as modern earthy peasant language, in his speechs and writings to set the right tone, build the right rapport, to get his people to view him the way he wants and do things he wants.

Much of what Mao said and wrote after he took control first of the chinese communist party and then of china was not for the purpose of clarifying his own personal views, but for getting people to do what he wants. So what he said and wrote after 1930s were often emotive, earthy, and full of a lot of hot air.

So I would not take literal translations of what he says literally.

The best reference of Mao personal views on society, religion, afterlife, etc are probably to be found in more obscure early writtings from the 1920s, when communism movement was more ideological and he wasn't yet embroiled in the intrigues and power struggles of a taking control of a real party trying to seize power.

These writtings suggests he was personally as dialectic materialist and atheist as was possible to imagine.