That is what is taught to the average follower. Right down to the denomination. I remember being taught that it would be sinful to go to a Mass in the Catholic Church across the street from the church I attended as a child. I clearly remember wondering why that would be so, since both worshiped the same deity system.
Then, there were the Chick Tracts about the "Death Cookie," and other anti-Catholic nonsense. It's not a matter of what the leaders of Christianity think. It's about what is being taught. I'm sure the little Catholic kids were being taught to stay away from my childhood church, too. None ever stepped inside its door. Some people would even refuse to go to a wedding or a funeral at a different church. As teens, we were even warned not to date Catholics to avoid being "yoked unequally." And that was a Presbyterian Church, for pete's sake. Catholic kids got similar warnings.
And that's within Christianity. Teachings about exclusivity are common. Which returns me to the "core flaw" idea.
We're talking about this religion stuff from a relatively objective distance. Nobody pays any attention to us, really. The teachings still go on. Read the current Catechism of the Roman Catholic Church. That's where the core of the church lies. That is what is being taught.
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