Rightly Extreme Faith or Extremism?

In seminary, I learned that expressing one’s faith in a dedicated manner may result in others’ hurt. Beliefs inform practices that can conflict with one another within a tradition, and resulting actions can be offensive and even painful to those that disagree with another's interpretation of Scripture. This can create disillusionment over how to define one’s own tradition when there are so many variations of theology and resulting praxis under one religious umbrella. If a person claims to be a Christian, and says their beliefs and actions are Christian, how does one definitively name heresy from orthodoxy?

Protestantism chooses a more confounding road in this respect than Catholicism or Mormonism, with less than a standardized structure to lean on here. But for all Christians, in looking to the church fathers and the process of assembling creeds like that of Nicaea, we find that discerning the parameters of a tradition can be a painful process that inevitably includes this eventuality: labeling those who perceive themselves as dedicated, faithful leaders as heretics.

In seminary, I thankfully had nothing but positive experiences in navigating this complex framework with my classmates. Some topics are easier to tackle than others. Typically (read: never ever) did my seminary arguments result in plots to kill one another or anyone else for that matter. It was our dedication to our faith that precluded murder from our to-do list. Thus, when I find countless news reports and history lessons attaching heinous acts (whose definition I realize may also be debated, but for now, let's deem it as intentionally harming unsuspecting, innocent people) to a faith tradition, it boggles my mind. Shouldn't we all be able to agree that their acts are not an accurate representation of that tradition? Is that what we imply when we say "extremist"? Is this how we acknowledge that there is a whole group of people hiding out somewhere that agrees that this crime is attached to a major religion's tenants, and does their strength in even modest numbers here preclude the rest of us from presuming obvious heresy?

Is this simply an excruciating, almost unbearable aspect of my own Protestant acceptance of a lack of standardized, hierarchical governance (Feel free have a field day with this, Catholics and Mormons)? Self-perceived "right praxis" of a tradition has no worldwide (or even city, state or nationwide) Protestant appointed police. Clearly this could be a whole other post on my beliefs about the nature of God's guidance through this. More pertinently for this post, Protestants are not alone in being misrepresented and misperceived by hateful acts. In fact, in modern times in the Western world, we have suffered this less than other traditions like Islam.

Is this struggle then an excruciating aspect of being an extremely religious person in a world where extremists fly the same flag and have a louder media microphone?