Nichiren's vow and our vow

From the Opening of the Eyes:

In the final analysis, no matter how I am abandoned by gods and how much difficulty I encounter, I will uphold the Lotus Sutra at the cost of my own life. Sariputra could not attain Buddhahood after having practiced the way of Bodhisattva for as long as sixty kalpa because he could not endure the difficulty presented by a Brahman who asked him for his eyes. Those who had received the seed of Buddhahood from the Eternal Buddha and Daitsuchisho Buddha an incalculable number of kalpas ago could not obtain Buddhahood for as long as 500 or 3,000 dust-particle kala (gohyaku-jintengo or sanzen-jintengo) until they had listened to the preaching of the Lotus Sutra on Mt. Sacred Eagle in this world. It was because they had been misled by these 'evil friends' to abandon the Lotus Sutra. No matter what happens, abandoning the Lotus Sutra would cause us to be plunged into hell. - Nichiren Shu Kyotsu Hori translation

and

"I have made a vow. Even if someone says that he would make me the ruler of Japan on the condition to give up the Lotus Sutra and rely upon the Kanmuryo-ju-kyo for my salvation in the next life, or even if someone threatens me saying that he will execute my parents if I do not say 'Namu Amida Butsu,' and no matter how many great difficulties fall upon me, I will not submit to them until a man of wisdom defeats me by reason. These difficulties are like dust in the wind. I will never break my vow to become the eyes of Japan, and become a great vessel for Japan." Ibid

and especially, in English and Japanese:

"I Nichiren and my disciples will eventually attain Buddhahood as long as we maintain resolute faith despite our difficulties. Day and night I told my disciples never to hold doubts even should they lack heavenly protection or a peaceful life. Still they fail to listen and harbor doubts in their heart. In the face of stark reality, the foolish will forget the promises they have made."

WARE NARABI-NI WAGA DESHI SHONAN ARITOMO UTAGAU KOKORO NAKUBA JINNEN-NI BUKKAI-NI ITARUBESHI. TEN-NO KAGO NAKI KOTO-WO UTAGAWA-ZARE. GENSE-NO AN-NON NARAZARU KOTO-WO NAGEKA-ZARE. WAGA DESHI-NI CHOSEKI OSHIE SHIKADOMO UTAGAI-WO OKOSHITE MINA SUTEKEN. TSUTANAKI MONONO NARAI-WA YAKUSOKU-SESHI KOTO-WO MAKOTO-NO TOKI-WA WASURURU NARUBESHI.