The thing is, you see, that it's impossible for an atheist to be nice as they don't have the example of God's niceness to follow, so the people who are being nice to people and think they're atheists can't possibly actually be true atheists at all. Conversely, Christians have always and throughout history forevermore only been nice to people, so any time you observe a Christian being less than nice, that's not a true Christian at all. Therefore, this survey proves that only Christians are nice to people. QED