The past decade has highlighted quite a bit of division within islam. Most of it is moreso about power rather than religious ideology per se.
The sunni/shia divide in the countries bordering iran. And while there are some manifestations of difference in practice on the ground, there's a lot of back and forth about who's more correct.
The divisions within sunni islam are the most troubling because they are very divisive, particularly in a community with underlying social problems.
In christianity, divisions within protestantism are called demonimations. People are lutheran, presbyterian, baptist, etc but ultimately they all unite as christians and have amassed a significant amount of political power under that banner.
However in islam, any slight difference in minhaj/denomination or adjustment to minhaj will have others identify you as deviant because you've deviated from what they view as the correct way or the straight path.
We have quran and we have sunnah/hadiths. Hadiths are like the gospel but its verifiable through a chain of narration rather than heresy. The different schools of thought are interpretations of these two bodies of knowledge and people in general go w whatever floats there boat.
Sometimes it gets a little tricky when jummats/congregations begin to adjust the generally accepted minhaj to suit their agendas because in order to justify the deviation you have to discredit others.
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