Why do churches do what they do? What is the biblical basis of church leadership structure? Why do certain traditions get entrenched? How did we arrive at our doctrines?
For far too many, Christian unity means standardless ecumenicism and compromise. The watered-down Church, unable to articulate its own principles any longer, opens its doors to every sort of pop culture idea, preferring "relevance" to the Gospel, accommodation to righteousness, and conciliation to truth. This results in churches and denominations embracing anti-biblical doctrines and politically leftist ideas like social justice, abortion, and critical race theory; or heresies like reducing Jesus to nothing more than a great teacher, eliminating any mention of sin, or turning God into an absentee landlord.
On the other side of the coin, there are Christians for whom unity is possible only of those who belong to a narrow, exclusive club comprised of those who share exacting beliefs. They create a long and detailed list of doctrines for which there must be lock-step agreement before any fellowship with another Christian is permitted.
These "Doctrinal Police" create workarounds to justify their separation, the most common of which is their claim that embracing a different doctrine is gross heresy, making the person not a Christian. That is, if someone believes something different, they are not saved and not entitled to consideration. they are not even deserving of prayer.