Some ideas and beliefs we hold allow for some give and take. Other ideas, however, no matter how much our opponents logically refute them, we hold on to as though our whole self-identity depended on them. Which, they do. These are our tribal markers.
How do you know your tribal markers? If you’re in a debate about what you believe, and you are willing to cede some of your arguments to your opponent, then those particular beliefs are not foundational to your identity. But, if you and your opponent reach a point at which you have no other argument to offer than to say, “You just don’t understand. My people understand. We will just have to agree to disagree.” Then you have found your tribal marker.
For example, Charismatic “speaking in tongues” is one such tribal marker. Speaking in tongues is not essential to being a christian, but it is essential to being a Charismatic. If one stops doing it, one is no longer a Charismatic. It is essential to the identity. A Calvinist’s “predestination” beliefs are tribal markers as well.
The more radical the marker, the smaller the tribe, and the less one has to use logical thought to defend it. The more a group insists upon and refines a tribal marker, the more people will be excluded from the group.