Nichiren warns Soka Gakkai cult members

"If one propounds that the True Law exists outside the sutras expounded by the Buddha, it shall be known as a preaching of the Devil of the Sixth Heaven" (Gosho Zenshu, p. 181).   

"Depend upon the preachings of the Buddha and do not put faith in traditions handed down orally" (MW-3, p. 156), 

and 

"Rely on the teachings of the Buddha, not persons" (Gosho Zenshu, p. 367).