Sectarianism are moves away from something "mainstream". Usually, these movements have been a critique of some kind or other. The movements have been political, as well, as religious. These movements have come to identify people in ideological frames, which are meaning-making.
In Christian tradition, Protestants have understood themselves as "distinct from" Catholicism. And Catholicism was a break away from Judiasm, in the early Church's founding. Each 'sect" sought a more "pure form" of religious expression, in more 'pure definitions" that become abstract systems of philosophical discourse. This was the "project" of theological reflection.
In the political realm, theology sought to give a reason for political subversion, reformation or revolution. But, theology was always "after the fact" of political upheavel or scientific inquiry. Theology has always been about addressing and maintaining the "social order" and the "social structures" and institutions that make up civilization.
Political ideology has been based mostly on the social factors of economics, but has also been based on religious freedom, which was our country's founding heritage. How we live and are in the world has much to do with the political philosophy that holds the reins of power and their tolerance of religious conviction.
In America, we believe that freedom is of uptmost importance, as without freedom, the individual is nothing more than a slave in mind or life. So, it is imperative to address the political realm, as apart from addressing this area, there is no ability for individual flourishing, religious freedom or human rights.
The problem for today's world, is the question of religious freedom where it concern human rights or liberties. Should there be State mandated vaccinations for the young, irregardless of the families' religious convictions? Should there be a tolerance of "faith healings" when there have been deaths reported by such convictions? Should there be tolerance of 'honor killings" because of the religious conviction of "property rights' where it concerns women? What is the position of our country and it's ultimate values?
There have always been movements that have sought to "correct" or "address" a problem, as identified by some 'standard'. We live in an imperfect world, and these movements were/are to seek the "ideal". Unfortunately, the "ideal" will never be found. So, it is best to maintain one's freedom from any form of groupish mentality that would tend to seek to "perfect" the individual or society. One can only perfect what they deem needful, which cannot be defined by others. But, it can allow freedom of discourse, which is a beginning to understand and evaluate freedom's assests in assessing and committing to one's highest, or best "ideal" of society or individual. I find that America's government is the closest.