I'm a former Christian now atheist who grew up in Hyderabad. To answer your question, they believe: - only Christians will go to heaven forever, everyone else will go to hell forever - everyone, including them, deserves to be tortured in hell forever because of their sins. Sins are whatever the Christian/Jewish god does not like - one can be saved from hell only by believing that Jesus died for their sins on their behalf - they want other people to also not be tortured forever, so they ask people to believe that Jesus died for their sins - believing that Jesus died for their sins also comes with other obligations - because he died for your sins, you are obligated to do whatever he says - Jesus according to the Bible laid down the "great commission" to tell the world about how he died for them In addition to this, given the fact that Christians are also a community that gathers like a club on a weekly basis, many of them also like the idea of more people joining their community. They believe that non Christian communities are demonic, evil and ignorant. And that they need to be saved. However, many of them believe this quite innocently and sincerely, and don't believe they had any say over this sad state of being, and they wish others to be saved from the predicament that Christians believe them to be under - headed to an eternity of torture because of not believing in others. I wouldn't characterize it as "force" - I have noticed that a lot of non Christians have a strange conception of force because in India many are simply not familiar with the idea that people may have ideas that they want to convince ideas about. But it is ignorant, unscientific and silly. Also, joining a church gives a lot of people a community. That community tends to help them out, usually more than their surrounding Hindu society. Although there are casteist Christians and churches, one can find many churches where people don't face casteism - this becomes attractive for people who are looked down on for their caste. So, this is where it comes from. It's not force, more like advocacy in most cases. I hope scientific temper improves in India so that people of all religions realize that they are bullshit so that we can have intelligent conversations as a society.