Does the noble Hadith: "The Jews divided into seventy-one sects, and the Christians divided into seventy-two sects, and this Ummah will divide into seventy-three sects, all of them in the Fire except one." They asked, "Who are they, O Messenger of Allah?" He said, "That which I and my Companions are upon," promote division among Muslims, such as distinguishing between those who adhere to the Sunnah and those who do not?

The aforementioned hadith informs about the schism that will occur, and does not endorse it. This is part of Allah's informing His Messenger about certain unseen matters. The Muslim nation is required to unify and gather upon the Qur'an and Sunnah, and it is not permissible for it to diverge. The blameworthy disagreement is in matters of creed and fundamental principles, not in the disagreement among the followers of the jurisprudential schools of thought.