Religion exists to explain the "unexplainable." To make sense of a world that may seem frightening at times or overtly cruel and unsympathetic. Religion is this context is fine and useful as long as it continues to help others.
But organized religion is Man's religion, not any God's. Then it becomes aggressive, adversarial, and controlling - which in the end is its main objective.
When a religion gets down to dictating what clothing to wear, whether to cover one's face or not, and that women are inherently inferior - do you really think "God" is just letting everyone know what he's all about? I think not.
John Chau eventually lost sight of his humanity, let alone his calling. Too bad. Could have been a much better ending to that story.