"what Christianity says"

That's kind of the problem right there. Religion has always been a way to garner money and power along with a smattering of explaining the unexplained. It's a collection of fairytales with a little spice of real history designed to keep it's people feeling indebted, donating and coming back. Any thing that requires blind faith should lead you to be extremely suspect about "their message".

The stories, the psalms, the mass singing, the praise of the long absent mystical deity, it's all psychological conditioning. The preacher running the guilt trips interspersed with good morale messages, none of this is making any of those people better people.

Christianity did not catch on because it was popular with the poor, it caught on because the people running it are masters of psychological manipulation. The poor don't stand up Christianity, the congregations aren't made up of paupers.