The Fairytale of Christianity

Everyone knows what a fairytale ending is like, the main characters run away and get married, the evil villain dies or goes to prison for the rest of their life, the sick person gets better and those who were lost are found and reunited with their loved ones. Why does humanity long for happy endings? And more importantly, is that the only reason that Christianity is so popular? Do Christians base their life on a fictional story that has no truth in it but simply makes them 'feel good' about life?