While I struggle with Gene Reeves and Risshō Kōsei Kai’s doctrine of Interfaith Truth, I have no real problem with the idea that the ocean of the Lotus Sutra contains all of the rivers of Buddhist thought.

As Reeves states in his discussion of Chapter 22, Transmission, in his Stories of the Lotus Sutra:

As the Dharma Flower Sutra often praises itself and asserts its own excellence or superiority, it is very important to notice that in [Chapter 22, Transmission], which entrusts the teaching to bodhisattvas, the Buddha says that if in the future there are people who cannot have faith in or accept the Dharma Flower Sutra, other profound teachings of the Buddha should be used in order to teach the Dharma Flower Sutra. In other words, the teachings of the Lotus Sutra are not only in the text called the Sutra of the Lotus Flower of the Wonderful Dharma, they are also to be found in all of the profound teachings of the Buddha found in numerous sutras. By clinging too strongly to the text and words that we call the Dharma Flower Sutra, we may limit our ability to spread the teachings of the Sutra, the teachings that comprise the “real” Dharma Flower Sutra.

The Stories of the Lotus Sutra, p235-236

Later in the same chapter he expands on the need for a “generous attitude” when expounding the Lotus Sutra.

It is common for people who are enthusiastic about something to want to protect it by preserving it just as it is and by taking pleasure in making it difficult for it to be understood or appreciated by the uninitiated. Being inflexible about how a text is to be translated and expressed, insisting, for example, on using unfamiliar Sanskrit terms or quaint English expressions, may make it very difficult for others to enter a particular circle of understanding and appropriation. In such ways we may be establishing an in-group/out-group situation in which we are on the inside, in some way perhaps protected from what is outside. Traditionally, secret religious doctrines or ceremonies often functioned in this way.

Perhaps this kind of group bonding through special, esoteric language is necessary to some degree. Certainly it is very common among religious groups. But when it means that the Dharma Flower Sutra, which entrusts us to spread it everywhere, is not taught generously to others, we fail to fulfill the commission of the Buddha.

I believe that teaching generously should mean that we share the Sutra in whatever ways are most appropriate to the intended audience, always, of course, within the real limits of our abilities. While it might be nice if everyone learned enough Chinese to be able to read Kumarajiva’s Chinese version of the Lotus Sutra, this is neither necessary nor necessarily desirable. It is good, I believe, that we have versions of the Dharma Flower Sutra that make it more intelligible to Japanese people, and it is good that there are English versions that make it more available to English-speaking people. This is not merely a matter of translation into other languages; it is important that the Sutra be rendered in ways that make it as understandable as possible.

This kind of generosity, a generosity in which one tries to understand and appreciate the linguistic and cultural situation of others, a generosity in which we do not insist that our own way of expressing something in the Sutra is the only good way, this kind of generosity is what the Sutra expects of those who are its genuine followers.

If we do not approach teaching the Sutra with such a generous attitude we will, I fear, fall into one more version of “merely formal Dharma.” In other words, we will be going through the motions of teaching and practicing, but very few will be deeply moved by such teaching. This kind of failure to be generous is largely unconscious, making it difficult, but not impossible, to detect and overcome. But another problem often stands in the way of our being generous in teaching: Often we are all too conscious of it, making it difficult to overcome. This is manifest in reticence or shyness in speaking and teaching.

The Stories of the Lotus Sutra, p237-239

For me this is all underscored in Chapter 14, Peaceful Practices:

A Bodhisattva-mahāsattvas who wishes to expound this sūtra in the age of the decline of the teachings after my extinction should perform the following peaceful practices. When he expounds or reads this sūtra, he should not point out the faults of other persons or sūtras. He should not despise other teachers of the Dharma. He should not speak of the good points or bad points or the merits or demerits of others. He should not mention Śrāvakas by name when he blames them. Nor should he do so when he praises them. He should not have hostile feelings against them or dislike them. He should have this peace of mind so that he may not act against the wishes of the hearers. When he is asked questions, he should not answer by the teachings of the Lesser Vehicle, but expound the Dharma only by the teachings of the Great Vehicle so that the questioners may be able to obtain the knowledge of the equality and differences of all things.”

And again later:

“Again, Mañjuśrī! A Bodhisattva-mahāsattvas who wishes to keep, read and recite this sūtra in the latter days after [my extinction] when the teachings are about to be destroyed, should not nurse jealousy against others, or flatter or deceive them. He should not despise those who study the Way to Buddhahood in any way. He should not speak ill of them or try to point out their faults. Some bhikṣus, bhikṣunīs, upāsakās or upāsikās will seek Śrāvakahood or Pratyekabuddhahood or the Way of Bodhisattvas. He should not disturb or perplex them by saying to them, ‘You are far from enlightenment. You cannot obtain the knowledge of the equality and differences of all things because you are licentious and lazy in seeking enlightenment.’ He should not have fruitless disputes or quarrels about the teachings with others. He should have great compassion towards all living beings. He should look upon all the Tathāgatas as his loving fathers, and upon all the Bodhisattvas as his great teachers. He should bow to all the great Bodhisattvas of the worlds of the ten quarters respectfully and from the bottom of his heart. He should expound the Dharma to all living beings without partiality. He should be obedient to the Dharma. He should not add anything to the Dharma or take away anything from the Dharma. He should not expound more teachings to those who love the Dharma more [than others do].

Yes, Nichiren didn’t appear to be so understanding or tolerant, but this is not 13th century Japan. This is a much different world. As Ryuei McCormick explained in his earlier reply to my inter-faith question, “Nichiren makes it clear that there are countries that are just ignorant and evil and then there are countries that slander. I believe the distinction he is making is between non-Buddhist cultures that need to be persuaded to give ear to the Dharma and learn more about it until they are able to take up the Wonderful Dharma of the Lotus Sutra.”