On the palm of a man named Mahānāma a pebble changed to a precious stone. King Konzoku is said to have been able to transform sand into gold. The Lotus Sūtra enables even insentient beings such as grass and trees to attain Buddhahood, not to speak of sentient beings that possess minds such as humans. The Lotus Sūtra enables the Two Vehicles whose seed of Buddhahood has been burned to attain Buddhahood, how much more so with people whose seed of Buddhahood is still alive! Moreover, the Lotus Sūtra enables even the icchantika who has no religious belief to attain Buddhahood, how much more it will lead those with religious faith.

Ueno-dono Gohenji, Reply to Lord Ueno, Writings of Nichiren Shōnin, Volume 7, Followers II, Page 33

Once upon a time, a man who had offered a “rice cake” made from mud to a Buddha ascended the throne in a kingdom due to this virtuous act. As the Lotus Sūtra is the dharma superior to a Buddha, those who make donations to the sūtra will inevitably gain blessings in this life and attain Buddhahood in the future lives, will they not?

Kurōtarō-dono Gohenji, A Reply to Lord Kurōtarō, Writings of Nichiren Shōnin, Faith and Practice, Volume 4, Page 153

And yet even though a finger might point to the great earth and miss it, a person tie up the sky, the ocean’s tide lack an ebb and flow, or if the sun should rises in the west, there cannot be a time when the prayer of a practicer of the Lotus Sūtra is not answered. If the various bodhisattvas, human and heavenly beings, eight kinds of gods and demi-gods who protect Buddhism, the two sage bodhisattvas (Medicine King and Brave Donor Bodhisattvas), two heavenly kings (Jikoku-ten and Bishamon-ten), and ten female rākṣasa demons, or even one out of 1,000, do not rush to protect practicers of the Lotus Sūtra, they commit the sin of fooling Śākyamuni and the other Buddhas above and in the nine realms below. Thus, they will protect the practicers of the Lotus Sūtra without fail regardless if the practicers are insincere, unwise, impure, and do not observe the precepts so long as they chant “Namu Myōhō Renge Kyō.”

Kitō Shō, Treatise on Prayers, Writings of Nichiren Shōnin, Faith and Practice, Volume 4, Page 68

Regarding the sūtras, the Lotus Sūtra is the most supreme among all exoteric and esoteric teachings. Regarding the Buddhas, Śākyamuni Buddha is the most supreme among all the Buddhas in all the worlds throughout the universe. Regarding those who practice the faith, Nichiren is worthy of being a practicer of the Lotus Sūtra. When the “three treasures” in Buddhism (the Buddha, Dharma and Sangha) are aligned with one another, there can be no doubt that your most sincere hopes and wishes will be realized.

Niita-dono Gosho, A Letter to Lord Niita, Writings of Nichiren Shōnin, Volume 7, Followers II, Pages 106-107

The reason why those who had received the seed of Buddhahood in the eternal past have been transmigrating the six realms (lower states of existence) ever since for as long as “500 dust-particle kalpa” without attaining Buddhahood, and those who had heard the Lotus Sūtra at the time of the Great Universal Wisdom Buddha have been undergoing transmigration in the six realms ever since for the “3,000 dust-particle kalpa” was because they abandoned the great teaching of the Lotus, seeking refuge instead in expedient and Hinayāna sūtras preached forty years or so before the Lotus Sūtra. Later they gave up faith in those expedient sūtras, too, and thus have continued to transmigrate through the six realms.

Shugo Kokka-ron, Treatise on Protecting the Nation, Writings of Nichiren Shōnin, Doctrine 1, Page 42

The Lotus Sūtra, fascicle 5 (15th chapter on “The Appearance of Bodhisattvas from Underground”) preaches, “I have always taught them in their past existence… , and as soon as they saw Me and heard My preaching in this life, they received My teachings by faith, entering into the wisdom of the Buddha.” Interpreting this, Grand Master T’ien-t’ai states in his Words and Phrases of the Lotus Sūtra, “People today were taught and received the seed of Buddhahood in the eternal past.” Grand Master Miao-lê, on the other hand, declares in his Annotations on the Words and Phrases of the Lotus Sūtra, “Although it is in the present when people gain the benefit of attaining Buddhahood, the seed of Buddhahood was sown in the eternal past,” and in his Commentary on the Profound Meaning of the Lotus Sūtra, “Thus I know that the preaching of Śākyamuni Buddha today is for those in whom the seed of Buddhahood was sown in a past existence.” I do not have to explain what is said in the sūtra and its annotations, which are very clear in meaning.

Soya Nyūdō-dono-gari Gosho, A Letter to Lay Priest Lord Soya, Writings of Nichiren Shōnin, Doctrine 3, Pages 150.