The reason why such śrāvaka disciples as Śāripūtra and Maudgalyāyana were in the Hell of Incessant Suffering for as long as 3,000 or 500 (million) dust-particle kalpa was not because they committed the crime of ten evil acts, five rebellious sins, or eight rebellious sins such as treason. It was simply because they met “evil friends,” abandoned the faith in the Lotus Sūtra, and moved to the faith in the expedient teachings. Grand Master T’ien-t’ai explains this in his Profound Meaning of the Lotus Sūtra, fascicle 6, “Upon meeting an ‘evil friend,’ people lose their right mind.” The right mind refers to the mind of putting faith in the Lotus Sūtra, and losing the right mind means abandoning the faith in the Lotus Sūtra and putting faith in other sūtras. Therefore, it is preached in the Lotus Sūtra, “The Life Span of the Buddha” chapter, “No matter how effective a medicine is, such a person will never take it.” This is explained by Grand Master T’ien-ta’i in his Profound Meaning of the Lotus Sūtra, fascicle 6, “A person who has lost his right mind will not take a good medicine, no matter how effective it is, choosing instead to roam about the street of life and death, and run away to foreign countries.”
Kyōdai-shō, A Letter to the Ikegami Brothers, Writings of Nichiren Shōnin, Volume 6, Followers I, Page 75