The Gohonzon is the very entity of the enlightened life of the Original True Buddha (honbutsu 本仏). The Original Buddha attained instant enlightenment in the beginningless past of kuon-ganjo through the fusion of reality and wisdom (kyochi myogo 境智冥合), as a common mortal. This Buddha itself embodies the ultimate truth of Myoho-Renge-Kyo, and appeared in Mappo as Nichiren Daishonin. Nichiren Daishonin inscribed his inner realization (naisho) into the Gohonzon of the High Sanctuary for the sake of the enlightenment of all beings in this Jambudvipa world.Now in the second year of Koan (1279), it is twenty seven years since I first proclaimed the true teaching....The Buddha fulfilled the purpose of his advent in a little over forty years; T'ien-t'ai took about thirty years, and Dengyo, some twenty years. I have repeatedly spoken of the indescribable persecutions they suffered during those years. For me it took twenty-seven years.
(Gosho, p. 1397)
Nichiren Daishonin indeed states in "Reply to Kyo'o" ("Kyo'o dono-gohenji"),
If you chant Nam-Myoho-Renge-Kyo with absolute, unwavering faith in the Gohonzon, and practice in accordance with the Lifeblood Heritage of the Law entrusted to a single person (yuiju ichinin kechimyaku sojo), you can transform your countless delusions into enlightenment and your sufferings into happiness.I, Nichiren, have inscribed my life in sumi, so believe in the Gohonzon with your whole heart. The Buddha's will is the Lotus Sutra, but the soul of Nichiren is nothing other than Nam-myoho-renge-kyo....Muster your faith and pray to this Gohonzon. Then what is there that cannot be achieved?
(Gosho, p. 685)