One question for religious folks here, why is good not good enough?
As far as the Christian perspective goes, being "good" is not the point to salvation. It's like saying, "I wear shirts and eat chicken for dinner 3x a week, why don't I get to go to heaven?" It has nothing to do with what God expects for salvation. The idea that "good people should go to heaven" is a man-made idea.
Christianity is about Jesus Christ sacrificing himself for the sins of mankind in general, not you or me in particular. The only way you get to heaven is accepting the sacrifice Christ made for us all. You or I can't be good enough to atone for the sins of mankind, only Jesus could do that. To use another silly analogy, from God's perspective, it might be like me saying, "Hey I'm a good guy, I rarely swear and I treat people nicely. So can you just forget about that whole Holocaust thing, and us worshiping a bunch of other gods and things that aren't You, plus the Rwandan genocide, and the Rape of Nanking, and..." God can only accept me or anyone else from the standpoint we are covered by Christ's sacrifice/atonement, when we accept that atonement.
You do understand why this belief sounds ridiculous to those who disagree, don't you? If the creator of the universe wants to eternally persecute me for failing to believe tales of magic for which no evidence exists, that makes him an asshole. I can't really interpret it in any other way (even after spending 30 years trying to convince myself that I did).
I'm not Doubledown, but yeah, I get it. You don't believe, and it's all magic. Cool. However, Doubledown was just answering a question. Why barge in with your hackles up, and be a dick?
I mean, if person 1 asked a Hindu about dharma, and person 2 answered, would you as person 3 flail around and start berating the poor Hindu their magical and ridiculous beliefs? Or would your good fucking manners kick in?
What is it about Christianity that causes everyone to become so unhinged and so goddamn aggressive?
That bolded question is a really good question. My guess as a hinged (?) non-Christian is that's it's a result of several factors:
1. The evangelizing part of Christianity. Aggressive evangelization can make people feel resistant.
2. The hell factor. Threats of hell up the emotional ante IMHO.
3. Cultural dominance. I grew up in the Bible Belt, Christians had vast numerical majority. Sure, there are others, but it's still easy for a non-Christian in much of America to feel outnumbered. Could increase the perceived need to sound aggressive.
4. Exclusivity. Unlike Buddhism or FSM or such, Christians usually feel that some specific thing has to happen for the person to be ok/saved/etc. So the discussion is difficult to end with satisfaction on both sides. From experience, the non-Christian can accumulate a lot of frustration. I'm very appreciative of Christians, but I can see how the frustration could appear later as aggression.
5. Secular state. We have room to discuss. Therefore people whose psyche has an argumentative feeling lurking within are free to transfer that feeling into religion.
In combination, these things could leave someone in a sort of hair trigger state, ready to boil into anger given the opportunity.
Fwiw, I think there are fewer such discussions than at many other times and places. Which reminds me of a friend of mine. One time he was renting a room in my house and his visiting girlfriend was screaming at him. Later I asked how he could stay so calm. "She's never had a safe place to yell before," he replied. "She's not always like that. I think she'll work through it." IIRC, she more or less did. Perhaps some these incidents that look like unprovoked aggression at the incident level are part of a broader process of releasing the steam from the system, reducing the pressure over time. (If we turn the other cheek in response, so to speak.)