Are people truly happy in North Korea?
Happiness is indeed a human condition. But within the Org as with North Korea everyone is on tenterhooks in case they step out of line and get slapped.
It is impossible to be truly happy when you are worried that someone of your (supposed) friends might report you for a word spoken out of turn, or a joke with a double meaning you happened to tell.
Christianity is supposed to draw people closer to the Divine Nature, not make them feel afraid, shameful, or guilty 100% of the time.
All Christian religions will be happier doing what the written word of God instructs them to do to follow the path. But once man-made extra conditions come in to control the person, then happiness flies out of the window!