Sunni and Shia Islam alike hold, as a matter that admits no real dispute inside either tradition, that God is one, without partner, body or human likeness, and that Muhammad ibn Abdullah, who died in 632, was the final prophet, after whom no valid prophet or messenger can come. The Nation of Islam's founding theology contradicts both points directly. Locating Allah in the physical person of Wallace Fard Muhammad breaks with the doctrine of divine transcendence that mainstream Muslim scholarship treats as inseparable from tawhid, the oneness of God, and casting Elijah Muhammad as a Messenger sent after Muhammad ibn Abdullah breaks with the finality of prophethood that nearly every Muslim community, however much it disagrees on other questions, holds without qualification. Mainstream Muslim organizations, in the United States and elsewhere, have for this reason consistently described the Nation of Islam's core theology as standing outside Islam as they understand it, whatever kinship the movement's practice, calendar and vocabulary otherwise show.
The Nation of Islam's own leadership has not been uniform in its response to that judgment. After Elijah Muhammad's death in 1975, his son Warith Deen Mohammed led the majority of the movement toward Sunni orthodoxy, explicitly setting aside the doctrine of Fard's divinity and Elijah Muhammad's messengership as his father had taught it. Louis Farrakhan rebuilt a separate organization retaining the Nation of Islam name and, with it, the original theology largely intact, so that the doctrine of Fard's divinity now describes one living reading of the movement's history rather than an uncontested consensus even among those who trace their lineage to it.