Specifically, 2007 years ago, because Jesus was born, as the first Christian.
Regarding fanaticism, I basically agree with you, but in my opinion, a fanatic is not someone who proves the correctness of their faith. Rather, it's a preacher. According to your logic, it turns out that we are both fanatics:D I am a Christian, and you are an atheist:) But if a person starts to impose their religion and insists that it is the only correct one, no matter what, then that is a fanatic, IMHO.
Regarding sectarians, are they Jehovah's Witnesses by any chance?:) You can make fun of them endlessly. They simply memorize certain passages from the Bible, go door-to-door, and then it begins: "Our God is this and that, because as it is written: 'tra-ta-ta'," and all other religions are false, because as it is written, "tra-ta-ta." I don't know exactly where it is written, but some believe that God has a name, and it is Jehovah, and that's how Jehovah's Witnesses came about. In their opinion, the end of the world has long since come, and we are all living in hell now:D When I was two years old, Jehovah's Witnesses came to my mother (she had recently converted to Christianity at the time). She opened the door, and they started: "tra-ta-ta-tra-ta-ta-tra-ta-ta." My mother saw that they were Christians, and she was happy and said to one of them, "Sister!" They immediately fell silent, and one of them suddenly asked, "What is God's name?" My mother, without hesitation and with reverence, replied, "Jesus Christ!" And the sectarians immediately left...:D
Regarding heaven and airplanes, it's funny, but the idea that God lives in heaven is complete nonsense, although who knows... But the preconceived notion that Paradise is clouds and meadows with flowers... Personally, I don't think that's the case. It's just that when they said that it was good in Paradise, people probably started thinking about it, and that's how this "prototype of Paradise" came about. For me personally, it's a country house, a garden, and playing knights with stick swords with friends (childhood memories).
Archer, I understand you, so I've already sent a message to the Creator to create a separate section for philosophy and everything related to it.
P.S. Now the times have changed, and people are divided not so much by the question of faith as by the question of politics;)