In light of the comments, I want to write about sectarianism.
Sectarianism is a focus on specific or special forms of identification factors. Universalism, on the other hand, is a focus on a generalized or common trait.
Sectarians separate themselves due to offense to specified behaviors or beliefs that they think are heretical. Sectarians separate to maintain their identity and define themselves as "special" or "set apart" or "holy". But, they limit their understanding of themselves in real ways and in real terms of a human being. Thus, labels are good for defining these behaviors or beliefs and creating a "false sense" of protection and distance from "evil" and "the world".
Sectarians define things in black and white terms. They do not like or think in bridging the gaps, thinking in shades of grey, because they fear stepping over a forbidden boundary. These are religious ways of understanding oneself and can be damning in developing a self identity.
What sectarians don't know is that all boundaries are made by men, even when they are in texts or define the boundaries of a culture. Cultrues are defined by social norms, and values. The "human" way of looking at things is to identify with another as a "person", a human being. Then, relationship is more about mutual commonality, than in differences.
1 hour ago