The reason why those who had received the seed of Buddhahood in the eternal past have been transmigrating the six realms (lower states of existence) ever since for as long as “500 dust-particle kalpa” without attaining Buddhahood, and those who had heard the Lotus Sūtra at the time of the Great Universal Wisdom Buddha have been undergoing transmigration in the six realms ever since for the “3,000 dust-particle kalpa” was because they abandoned the great teaching of the Lotus, seeking refuge instead in expedient and Hinayāna sūtras preached forty years or so before the Lotus Sūtra. Later they gave up faith in those expedient sūtras, too, and thus have continued to transmigrate through the six realms.

Shugo Kokka-ron, Treatise on Protecting the Nation, Writings of Nichiren Shōnin, Doctrine 1, Page 42