I agree with you that Christians should unite under Christ and following what he has set for you, not somebody else. Most of the causes for the division between Christians come from humans and their interpretations of Jesus' words and try to force them on others. Each person is allowed to have his/her own interpretations of Jesus' words, because Jesus never said this is what I mean and there's no deviation from it after every lessons he taught. His utmost law is, as you said, "Love one another as I've loved you." Are wars over the differences of interpretations following this law? Definitely not.

This is the first time I've seen somebody made the connection between the Church and fandoms, but I've got to say that what you've said are right. Although HP fandom is the only one that I've participated in, it is still enough for me to roll my eyes sometimes. People have got to stop all these defences they've built up that wall off every criticism towards their favorite characters. That's just plain unreasonable. While it's true that you don't have to agree with another fan's perspective of the book or the character, you don't need to force your perspective on them, either. That's one of the reasons it's hard to have rational discussions with fans sometimes. They aren't willing to compromise to the sake of learning.

~Shina Laris