History and Teachings of Nichiren Buddhism, p 91-92Śākyamuni Buddha does not abandon us perverted people.
“I am always thinking:
‘How shall I cause all living beings
To enter into the unsurpassed Way
And quickly become Buddhas?”‘With this vow, Śākyamuni Buddha, as the Eternal Buddha, is constantly lending a helping hand to us perverted people.
How do the activities of the Buddha toward the salvation of others over eternity develop? In “The Duration of the Life of the Tathāgata,” these activities are revealed in the form of the six occasions of showing the deeds and figures of buddhas.
I told the stories of my previous lives in some sūtras, and the stories of previous lives of other Buddhas in other sutras. I showed my replicas in some sūtras, and my transformations in other sūtras. I described my deeds in some sūtras, and the deeds of others in other sūtras.
Śākyamuni Buddha is always leading us into salvation, showing himself in many guises and using many different methods. Right before the Assembly in Space begins, many buddhas were invited. These were actually manifestations of the Eternal Buddha. This reveals why they are called manifestations. Many buddhas besides Śākyamuni Buddha appear in Buddhism, for example, Amitābha Buddha and Medicine Master Buddha. Each of these buddhas is viewed as a part of the Eternal Buddha. Even the historical Śākyamuni Buddha, whose lifespan was limited, is viewed as one aspect of the Eternal Buddha. In this way, all the buddhas working toward the salvation of living beings are merely different manifestations of the eternal Buddha, who uses the six occasions of revealing the deeds and figures of buddhas to show himself appropriately in each situation.
It may seem that so long as we remember that the Eternal Buddha is at the base of the individual Buddhas, we can put our faith in any Buddha. Nichiren Shōnin severely criticized such a theory, saying that it makes light of the base and emphasizes trivial details.