"Question: If that is so, then why do you not take Shakyamuni as your object of devotion, but instead make the daimoku of the Lotus Sutra the object of devotion? Answer: [...] This is not a matter that I have decided for myself. Shakyamuni Buddha and T’ien-t’ai are the ones who have declared that the Lotus Sutra should be the object of devotion. And now, in this latter age, I, Nichiren, too, following the example of the Buddha and T’ien-t’ai, take the Lotus Sutra as the object of devotion. I do so because the Lotus Sutra is the father and mother of Shakyamuni Buddha, the eye of the Buddhas. Shakyamuni, Maha-vairochana, and all the other Buddhas of the tendirections were born from the Lotus Sutra. Therefore, as the object of devotion I now take that which is capable of bringing forth such life force."
From Gosho "Questions and Answers on the Object of Devotion" (The Writings of Nichiren Daishonin Volume II, pages 788-789)
From Gosho "Questions and Answers on the Object of Devotion" (The Writings of Nichiren Daishonin Volume II, pages 788-789)