Sects and division

The argument assumes that a true religion would produce uniform agreement among its adherents. Stated that plainly, it is worth asking who ever promised that.

What the tradition actually says

The Prophet foretold that the community would divide into many groups. The number given, seventy-three, is a figure of speech for multiplicity in the idiom of the time, in the way that “forty” or “a thousand” functions across Semitic languages. Reading it as a census is a category error, and the polemic that counts sects and matches them against the number has misunderstood the sentence it is quoting.

The relevant point is that the division was predicted rather than denied. A religion whose founder said the community would fracture is not embarrassed by the fracture.

Disagreement is not schism

Most of what gets counted as sectarian division is fiqh (jurisprudence): differences over how a ruling is derived and applied. Four Sunni legal schools coexisted for over a millennium, each holding the others valid, and a Muslim may follow any of them. That is a structured method for handling disagreement rather than evidence of collapse, and the tradition built it deliberately.

The genuinely serious divisions are narrow, and Muslims have argued about where the boundaries fall with more rigour than the objection credits.

The test the argument fails

Apply it elsewhere. Christianity numbers its denominations in the thousands. Judaism, Buddhism, and every school of secular philosophy have fractured comparably. If internal disagreement falsifies a position, nothing anyone has ever held survives, including the objection itself.

Disagreement among people who hold a thing is evidence about people. It is not evidence about the thing.