[C]hapter 16 is traditionally understood as showing that Shakyamuni is the Everlasting Original Buddha, and from that point of view, is regarded as the core of the second half of the Lotus Sutra. Since it does maintain the eternal life of Shakyamuni, such an interpretation certainly seems reasonable, but it is important to notice how that eternal life is taught.

The inception of the revelation of the everlasting life of Shakyamuni Buddha is in chapter 15, where a question is raised about the countless bodhisattvas who emerged from the earth and were said to have been taught from the remote past by Shakyamuni. Here at its inception, the teaching of the eternity of Shakyamuni Buddha is already related to bodhisattvas.

Thus, since I became Buddha a very long time has passed, a lifetime of innumerable countless eons of constantly living here and never entering extinction. Good sons, from the beginning I have practiced the bodhisattva way, and that life is not yet finished…

In short, unlimited, endless bodhisattva practice is used to demonstrate the eternal life of the Buddha.

In Christianity, where the absolute God of monotheism was affirmed, the relation between reason and faith became a big issue, and arguments developed around three positions—having faith in order to know, knowing in order to have faith, and having faith although it is irrational. In Buddhism, such serious arguments never arose, because the conception of God found in monotheism does not exist in Buddhism. In other words, the Everlasting Buddha of chapter 16 of the Lotus Sutra is essentially different from the One God, the supreme deity commonly seen in India, and from the monotheistic deity of Christianity and other religions.

Some readers may get the impression from [Chapter 16] that this everlasting, imperishable Shakyamuni Buddha is the personal God of monotheism. Hendrik Kern, who edited the Sanskrit text of the Lotus Sutra and translated it into English, had such an impression. His research led him to conclude that the Lotus Sutra is similar to the Bhagavad Gita and had been influenced by it. The Bhagavad Gita is presumably from about first century India. Its ancient religious poetry is full of songs of praise for a monotheistic and personal God. Most Indian people, down to the present, have come to love to recite its beautiful and passionate verses. …

Yet there is reason to disagree with this. Gita teaches a Creator and a cosmic creation, while in the Lotus Sutra the Everlasting Buddha is not regarded as the Creator, and there is no term equivalent to “creation.” Furthermore, the Bhagavad Gita emphasizes passionate and fanatical devotion (bhakti) to God, while we cannot find the idea of passionate and fanatical devotion to God anywhere in the Lotus Sutra.

Chapter 16, responding to the perplexity of people in chapter 15, explains that Shakyamuni Buddha is really the Everlasting Original Buddha using the metaphor of the five hundred dust particles worth of eons. Suppose someone ground into fine dust five hundred thousand billions of myriads (nayuta) of countless (asaṃkhya) three-thousand great thousandfold worlds, and just one particle of this dust was deposited on every five hundred thousand billions of myriads of innumerable lands until all of the dust was exhausted, and then all of these worlds, those with a particle of dust and those without, were ground into dust. If one particle of dust is regarded as equivalent to an eon, the period of time equivalent to all of the dust particles is nowhere near as long as it has been since Shakyamuni became a buddha.

An eon is a long time. A nayuta is usually taken to mean one hundred billion. The word asaṃkhya means an uncountable number. And “three-thousand great thousandfold worlds” refers to the result of adding together three kinds of thousandfold world—small, medium, and large. It is said that a small thousandfold world corresponds to the solar system, a medium one to the galaxy, and a large one to a nebula. In chapter 7, there is a story in which one of these three-thousand great thousandfold worlds is ground into particles of dust and one particle is deposited on every thousandth world. It is called “the parable of the three thousand dust particles of eons.” In short, the story emphasizes the Buddha’s eternal life by means of these similes of very large numbers.