The True Object of Worship, by Nichiren Daishonin Chapter 4 (Upholding the Lotus Sutra and Attaining Buddhahood), translated by Kyotsu Hori
Question (20): You have not responded to the serious question raise earlier regarding the Buddha residing in our minds, have you?
Answer: It is said in the Sutra of Infinite Meaning (Muryogi-kyo), an introductory teaching to the Lotus Sutra: "though unable to perform the six kinds of practice leading to Buddhahood: charity, observing precepts, perseverance, effort, meditation and wisdom, upholders of this sutra will inevitably receive the same merits as if they had practiced them." The second chapter of the Lotus Sutra states: "We wish to hear the way to perfection;" and in the Nirvana Sutra it is said: "'Sad' in the Saddharmapundarika (Lotus Sutra) means 'perfection'."
Bodhisattva Nagarjuna says in his great Wisdom Discourse (Daichido-ron) that "sad" means "six" while the Annotations on the Four Mahayana Treatises (Wu-i wu-te ta-cheng ssu-lun hsuan-i chi) by Hui-chun of T'ang China means "perfection" in India. The Annotations on the Meaning of the Lotus Sutra (Fa-hua i-su) by Chi-tsang states that "sad" is translated as "perfection"; while Grand Master T'ien-t'ai states in his Profound Meaning of the Lotus Sutra (Fa-hua hsuan-i) that "sad" is a Sanskrit term which is translated as "miao" (wonderful) in China.
I fear that I may debase these passages if I try to interpret them, but I dare do so in order to answer your question. The gist of these passages is that Sakyamuni Buddha's merit of practicing the bodhisattva way leading to Buddhahood, as well as that of preaching and saving all living beings since His attainment of Buddhahood are altogether contained in the five words of myo, ho, ren, ge, and kyo (Lotus Sutra of the Wonderful Dharma) and that consequently, when we uphold the five words, the merits which He accumulated before and after His attainment of Buddhahood are naturally transferred to us. Thus, it is stated in the Lotus Sutra (chapter four, "Understanding by Faith) that the four great sravaka such as Kasyapa rejoiced in their understanding of the teaching of the Lotus Sutra enabling sravaka to attain Buddhahood, and reported to the Buddha that they had been given invaluable jewels without asking for them. This represents the attainment of Buddhahood by the sravaka realm contained in our minds.
Not only the sravaka but also Sakyamuni Buddha is within us. For we encounter such a statement like this in the second chapter of the Lotus Sutra: "It was My (Sakyamuni's) original vow to let all beings become like Myself. My vow has now been fulfilled. I have helped them all enter the way of the Buddha." Does this not mean, that Sakyamuni Buddha, who has attained Perfect Enlightenment, is our flesh and blood, and all the merits He has accumulated before and after attaining Buddhahood are our bones?
Moreover, the eleventh chapter of the Lotus Sutra "Appearance of the Stupa of Treasures", states: "Those who uphold the teaching of this sutra are deemed to serve Me, Sakyamuni, and Taho Buddha. They also serve Buddhas in manifestation here who adorn and glorify their respective worlds." This means that Sakyamuni Buddha, Taho Buddha, and all the Buddhas in manifestation are in our minds, and that we, upholders of the Lotus Sutra, will follow their steps and inherit all the merits of those Buddhas.
This is the meaning of the passage in the tenth chapter of the Lotus Sutra, "The Teacher of the Dharma", which reads: "Those who hear of this Lotus Sutra even for a moment, will instantly attain Perfect Enlightenment." A passage in the sixteenth chapter of the Lotus Sutra, "Duration of the Life of the Buddha", contends: "It has been many hundreds of thousands of billions of nayuta of kalpa (an incalculably long period of time) since I have attained Buddhahood." It means that Sakyamuni buddha, within our minds, is an ancient Buddha without beginning, manifesting Himself in three bodies, and attained buddhahood in the eternal past described as 500 dust-particle kalpa ago.
In the same chapter, another passage reads: "The duration of My life, which I obtained through the practice of the way of bodhisattvas, has not yet expired. It is twice as long as the length of time stated above: 500 dust-particle kalpa." This reveals the bodhisattva-realm within out minds. The bodhisattvas described in the fifteenth chapter, "Appearance of Bodhisattvas from Underground", who have sprung out of the great earth, as numerous as the number of dust-particles of 1,000 worlds, are followers of the Original Buddha Sakyamuni who resides within our minds.
They are like T'ai-kung-wang and Duke of Chou, retainers of King Wu of the Chou dynasty in ancient China, who at the same time served the King's young son, King Ch'eng; or Takeuchi-no Sukune of ancient Japan, a leading minister to Empress Jingu, who concurrently served her son, Prince Nintoku. Just like them Bodhisattvas Jogyo, Muhengyo, Jogyo and Anryugyo, the four leaders of those bodhisattvas sprung up from the earth, are simultaneously followers of the Original Buddha and Bodhisattvas who reside in the minds of us, ordinary people.
Therefore, Grand Master Miao-le has declared in his Annotation on the Mo-ho chih-kuan (Mo-ho chih-kuan fu-hsing-chuan hung-chueh): "You should know that both our bodies and the land on which we live are a part of the 3,000 modes of existence which exist in our minds. Consequently, upon our attainment of Buddhahood, we are in complete agreement with the truth of '3,000 existences contained in one thought', and our single body and single thought permeate through all the worlds in the universe."