The reason why I speak ill of the doctrine established by Venerable Shan-tao is not due to my own conclusion. In ancient times, when Amitābha Buddha was practicing the bodhisattva way as King Mujōnen, he abandoned this Sahā World. So Śākyamuni Buddha, then called Bodhisattva Hōkai Bonji, took the responsibility of saving this Sahā World. When Amitābha Buddha and various Buddhas in the universe vowed not to welcome the slanderers of the True Dharma, the five rebellious sinners, and icchantika into the Pure Lands throughout the universe, Bodhisattva Hōkai Bonji vowed to save all those people rejected from the Pure Lands throughout the universe. Moreover, Śākyamuni Buddha preached in the Lotus Sūtra, “Only I will save and protect mankind.” “Only I” sounds haughty but it is not Śākyamuni Buddha’s own idea. As Amitābha Buddha and various Buddhas throughout the universe themselves abandoned the people in this Sahā World, so Śākyamuni vowed Himself, “Only I. …” Thus, He has already appeared in this Sahā World. Is there any room to doubt His intention?

Jōren-bō Gosho, A Letter to Jōren-bō, Writings of Nichiren Shōnin, Volume 5, Page 171