ReligionOfHatred. In Europe I never encountered anyone who would ever claim that A.H was atheist. In schools and media we were taught that he believed in his own version of God and Providence, and particularly disliked OT God as to be Jewish invention. Hitler was rather very religious, but it is more or less American invention to label him as atheist. It is only in USA when people associate him and his regime as atheistic. Stalin was probably religious, so did Khrushchev. Stalin suppose to be priest and had good understanding how religion can lead masses. His version of communism was modified religious movement. It had its saints, founders, mummy to worship, cult of personality.
When Hitler met with Stalin...
I am not aware that both dictators had ever met. I have read a lot of articles they tried to prove to do so, and they closest the research anyone had done seemed to point out that they may have met within Lviv area on the train for brief congratulation on destruction of Poland in October 1939 (Published by Edvard Radzinsky's biography Stalin, claiming that it happened in October 18, 1939). Either way, there is no definitive proof that both ever met face to face, but it is possible that they may run into each other in 1913, when they lived in Vienna (http://www.bbc.com/news/magazine-21859771).
Churches through its history were very selective on what disease deserved pity and support and what disease was seen as a punishment for sin and the victims were treated as they deserved. Typical issue is leprosy which was seen as a holy disease by Catholic church and its victims were cared of. People who got syphilis were treated with disgust as a sinner who deserved to suffer and die. This was going on until invention of salvarsan and later penicillin. Churches throughout Europe and later Northern America were refusing even burial for these victims. There was no mercy nor compassion. HIV in 1980-2015 is on the same spotlight as disease of the sinners by much of the christian community as was syphilis two centuries earlier.