The Nirvana Sūtra, fascicle 22, preaches: “You should not be afraid of evil elephants but should be fearful of the ‘evil friend.’ Why is this? It is because an evil elephant may hurt your body but not your heart. The ‘evil friend,’ however, may destroy both your body and mind. (…) Killed by evil elephants, you will not fall into the three evil realms, but if you are killed by an ‘evil friend,’ you will never fail to fall in the three evil realms.” Grand Master Chang-an interprets this in his Annotations on the Nirvana Sūtra: “Evil elephants cannot cause one to harbor an evil mind, but an ‘evil friend’ can cause one to have an evil mind through sweet words and flattery destroying the virtuous mind. The destruction of one’s virtuous mind is referred to as killing the man. Namely, the man goes to hell.” The meaning of this passage of Chang-an is that ‘evil friends’ destroy the virtuous mind of the ignorant by skillful use of words. To sum up the spirit of the Nirvana Sūtra, it warns us that those who slandered the Lotus Sūtra, which is the True Dharma, and icchantika are worse sinners than those who commit the sin of the ten evil acts and the five rebellious sins. The icchantika means those who slander the Lotus and Nirvana Sūtras.

Shō Hokke Daimoku-shō, Treastise on Chanting the Daimoku of the Lotus Sūtra, Writings of Nichiren Shōnin, Faith and Practice, Volume 4, Page 12

The term Tripiṭaka means three baskets: (1) basket of sūtras, (2) basket of monastic rules and (3) basket of commentaries. The teachings of the Buddha are thus classified and stored in three categories. The Tripiṭaka is further divided into the Three Learnings: (1) Buddhist precepts (kai), (2) meditation (iō), and (3) wisdom (e). It is sometimes said that there are jō, kai, and e in the order of the Buddha’s preaching; kai, jō, and e in the order of practicing; and e, kai, and jō with regard to the doctrinal teachings. In the precept basket, there are various kinds of precepts such as the Five Precepts, the Eight Precepts, the Ten Good Precepts, the Two Hundred Fifty Precepts, the Five Hundred Precepts and so on. In the meditation basket, there are such meditations as the Ambiguous Meditation, the Pure Meditation, the Meditation without Delusions, and so on. The basket of wisdom refers to the Buddha’s wisdom through which one can understand suffering, voidness, impermanence, egolessness, and so on.

Ichidai Shōgyō Tai-I, Outline of All the Holy Teachings of the Buddha, Writings of Nichiren Shōnin, Doctrine 3, Page 62

[I]t is stated in the Annotations on the Great Concentration and Insight that the book of the Great Concentration and Insight explains the way of practicing meditation based on the principle of the Lotus Sūtra and that the pre-Lotus, provisional sūtras are expedient means in preparation for preaching the True Dharma of the Lotus Sūtra. It means that the whole of the Great Concentration and Insight is based on the doctrine of “replacing provisional teachings with the true teaching” of the Lotus Sūtra. Therefore, although the Great Concentration and Insight quotes the pre-Lotus sūtras and non-Buddhist writings, it does not accept what is preached in them; it just borrows their sentences without meanings.

Jisshō-shō, A Treatise on the Ten Chapters of the Great Concentration and Insight, Writings of Nichiren Shōnin,
Doctrine 2, Page 2-3

Medicine King Bodhisattva burnt his elbows as a light to be offered to Lotus Sūtra for 72,000 years. Whenever Never Despising Bodhisattva saw anyone, he always recited the 24-character verse: I respect you deeply. I will never despise you because you are destined to practice the way of the bodhisattva and become Buddhas.” For many years he was the object of abuse of numerous men and women, priests and nuns, who beat him with sticks and threw stones at him.

This Never Despising Bodhisattva is the current Śākyamuni Buddha. What is more, King Suzudan in the past was so eager to learn the teaching of the five written characters, Myō, Hō, Ren, Ge, and Kyō, that he enslaved himself to the hermit Asita for a thousand years until he became the current Śākyamuni Buddha.

Nichimyō Shōnin Gosho, A Letter to Nichimyō Shōnin, Writings of Nichiren Shōnin, Followers II,
Volume 7, Page 138

Nevertheless, for what purpose did you take the trouble of sending a messenger all the way to this island? It was for the purpose of sending me the articles of offering in memory of the third-year memorial service for your beloved mother, which is an important matter in your life. To me, however, it was like a dream for a few days. I felt like Priest Shunkan of the Hosshōji Temple when he encountered his former boy servant of many years on Yuōjima Island [sic], where he had been exiled. When Duke Yang of a northern barbarian country was taken prisoner by the Chinese and brought southward from the north, he saw the wild geese flying northward, and sighed, saying, “They must be flying to my homeland.” I am sure that the sorrow the Duke Yang experienced then is not comparable to what I am undergoing today.

Nevertheless, it is preached in the Lotus Sūtra, “The Teacher of the Dharma” chapter, “Suppose there is a good person, man or woman, who can secretly preach even a phrase of the Lotus Sūtra for just one person after My (the Buddha’s) passing. You should know that such a person is a messenger of the Buddha, one who has been dispatched by the Buddha to carry out the work of the Buddha.” He who chants even one word or phrase of the Lotus Sūtra or explains it for the people is an envoy of the Lord Śākyamuni Buddha. Therefore, I am the person who has come to this country under the decree of the Lord Śākyamuni Buddha, though my social standing is humble. Accordingly, those who speak ill of me, even one word, will fall into the Hell of Incessant Suffering while those who speak even a word or phrase for me will gain the merits superior to that which is received by supporting numerous Buddhas.

Shijō Kingo-dono Gohenji, Response to Lord Shijō Kingo, Writings of Nichiren Shōnin, Followers I,
Volume 6, Page 119

Śākyamuni Buddha’s last words state that it is not non-Buddhist religions but Buddhists themselves that will destroy Buddhism, just as an insect living inside the body of a lion will eat up its flesh. In fact, some Buddhists destroy Mahāyāna teachings through Hinayana teachings while others extinguish the true Mahāyāna teachings by the provisional Mahāyāna teachings. These people, however, cannot exterminate the true Mahāyāna teaching of the Lotus Sūtra just as non-Buddhist religions cannot destroy Buddhism.

Hōmon Mōsaru-beki-yō no Koto, The Way to Refute the Evil Teaching, Writings of Nichiren Shōnin, Biography and Disciples, Volume 5, Page 155

What we should chant all the time as the practice of the perfect teaching is “Namu Myōhō Renge Kyō,” and what we should keep in mind is the way of meditation based on the truth of “3,000 existences contained in one thought.” Only wise men practice both chanting “Namu Myōhō Renge Kyō” and meditating on the truth of “3,000 existences contained in one thought.” Lay followers of Japan today should recite only “Namu Myōhō Renge Kyō.” As the name has the virtue of reaching the body for which it stands, when one chants “Namu Myōhō Renge Kyō” one will not fail to receive all the merit of the Lotus Sūtra.

Jisshō-shō, A Treatise on the Ten Chapters of the Great Concentration and Insight, Writings of Nichiren Shōnin,
Doctrine 2, Page 4

T’ien-t’ai’s interpretation makes it clear that even great bodhisattvas who have thoroughly studied Mahāyāna sūtras such as the Flower Garland Sūtra, Hōdō sūtras and the Wisdom Sūtra and reached the rank next only to the Buddha is incomparably inferior to those who merely listened to the Lotus Sūtra and had a connection with it, namely ordinary people in the Latter Age of Degeneration who were unable to eliminate the evil passions and master even one supernatural power.

Shō Hokke Daimoku-shō, Treastise on Chanting the Daimoku of the Lotus Sūtra, Writings of Nichiren Shōnin, Faith and Practice, Volume 4, Page 8-9

The use of the terms “eternity, joy, self and purity” by non-Buddhists in India were wrong in meaning, but they were so good as names that the Buddha used them to name the four kinds of virtues of Nirvana in Mahāyāna Buddhism later. However, the Buddha hated these terms at first in order to get rid of the non-Buddhist ideas. Even evil is the seed of Buddhahood, and so is virtue. Although the principle of emptiness to which śrāvaka and pratyekabuddha were stuck was virtuous, not evil at all, the Buddha reproached them in order to break their adherence to it. The nembutsu today destroys the Lotus Sūtra in this country. Therefore, the nembutsu must be denied and criticized even though it is good and not wrong in meaning for the sake of the Lotus Sūtra. It is because in Buddhism there is a suitable dharma for each country.

Jisshō-shō, A Treatise on the Ten Chapters of the Great Concentration and Insight, Writings of Nichiren Shōnin,
Doctrine 2, Page 5

In winter … trees appear dead, but pine and oak trees do not wither; grasses die, but chrysanthemums and bamboos remain unchanged. The same is true with the Lotus Sūtra, which will remain forever helping people even after other sūtras all disappear. Śākyamuni Buddha declared in the tenth chapter on “The Teacher of the Dharma” of the Lotus Sūtra that the Lotus Sūtra was supreme of all the sūtras He had preached, was preaching, and would be preaching. Moreover, in the eleventh chapter on the “Appearance of the Stupa of Treasures” the Buddha of Many Treasures attested the Lotus Sūtra to be true; and in the twenty-first chapter on “The Divine Powers of the Buddha” Buddhas manifested in various worlds all over the universe also verified the truth of the Lotus Sūtra by touching the Brahma Heaven with their tongues. Their sole purpose was to have the dharma of the Lotus Sūtra last forever in this world.

Shugo Kokka-ron, Treatise on Protecting the Nation, Writings of Nichiren Shōnin, Doctrine 1, Page 23