Guaranteeing Śākyamuni Buddha’s Eternity

From the standpoint of teachers of the Dharma and messengers of the Tathāgata, Śākyamuni Buddha must always be present, an eternal existence, so that they can maintain their practices unwaveringly. Śākyamuni Buddha’s constant and eternal presence supports them and encourages their activities, at times urging them on their way even strictly. With this realization they know that if they stop their activities, Śākyamuni Buddha’s activities are also stopped. Therefore, if the teachers of the Dharma and messengers of the Tathāgata do not act, Śākyamuni Buddha has no relation to us who live in the present age, becoming merely a buddha of a past age.

Therefore, you must become a teacher of the Dharma and a messenger of the Tathāgata! This is the greatest message of the Lotus Sūtra: to keep teachers of the Dharma and messengers of the Tathāgata present and active. This guarantees Śākyamuni Buddha’s eternity. The three orders in “Beholding the Stūpa of Treasures,” Chapter 11 of the Lotus Sūtra, are orders to become teachers of the Dharma and messengers of the Tathāgata, and to spread the message of the Lotus Sūtra into the future.

History and Teachings of Nichiren Buddhism, p 93-94