Siddhartha realized that he was the Buddha, Awakened One, and that his life embraced the whole of the Universe. Out of this realization came the understanding of his life and its purpose. He understood the concept of oneness—that the life of the Buddha is one with all other lives to the extent that there is nothing to separate or to distinguish them. He came to embrace all lives with compassion, experiencing all joys and all sadness as if they were his own.
That the Buddha’s enlightenment allowed him to see the death and rebirth of all living beings according to their karma was further indication of the oneness of his life with that of others. The Buddha embraced all lives with his compassion and became one with them. He was able to recognize others’ joy as his joy and others’ sadness as his own sadness. In the Nirvana Sutra, the Buddha said that all living beings received different sufferings and that those sufferings were actually his own sufferings.

Namu and the five characters became the seven characters of the Odaimoku, Na Mu Myo Ho Ren Ge Kyo. Namu, derived from the Sanskrit “Namas,” which means “to pay respect to, to revere.” It is generally used with regard to the Buddha or the three treasures (Buddha, Dharma, Sangha). It can be interpreted as a vow to the Buddha or as taking refuge. Namu means faith in the Buddha and oneness with the Buddha. Namu Myoho Renge Kyo means that faith in the Lotus Sūtra is equal to the Eternal Buddha and becoming one with the Buddha. It is also a vow that one will strive to become one with the Buddha. By taking refuge in the Lotus Sutra, one can enter the infinite life of the Buddha. One’s life merges into the Buddha’s life which is the Odaimoku, Namu Myoho Renge Kyo.

When we become one with the Buddha by practicing the Odaimoku, we enter into the world of the Great Mandala. It also means that we are participating in the ceremony in the air (assembly in the sky) where the Buddha preached the Lotus Sūtra. We are involved in the world of Ichinen Sanzen. It also means that the Great Mandala exists inside of our own bodies. Nichiren Shōnin states in Nichinyo Gozen Go-henji (Reply to Nichinyo):

“Do not try to obtain this honzon just anywhere, for it exists only in the flesh of those who have faith in the Lotus Sūtra and who chant ‘Namu Myoho Renge Kyo.”
(NOPPA Nyonin Gosho, p. 138)

What is the Great Mandala enshrined in the center of the altar? It is an image of the world of salvation expounded in the Lotus Sutra. It is a representation of the whole universe embraced by the Buddha’s compassion and illuminated with light of the Buddha’s wisdom. It is the Dharma World viewed from the Buddha’s enlightenment. The Great Mandala also represents three thousand worlds being held in the great life of the Buddha. It is the Buddha himself who has achieved an eternal life transcending the limit of time and space. Therefore, even though the Great Mandala is inscribed on a small sheet of paper, it should be recognized to be as vast as the universe.

The realm of Ichinen Sanzen of Ji is the realization of Śākyamuni Buddha within oneself. However, it is not true Ichinen Sanzen of Ji. It remains Ichinen Sanzen of Ri, the theoretical Ichinen Sanzen as the Buddha within oneself is still resting. If we say, ” Śākyamuni Buddha is in me,” we must make the Buddha within visible and active. This is the true meaning of Ji, to make the Buddha within us take form.

From the point of view of the Original Buddha, the nine realms are swallowed in the Buddha’s great life. We just do not notice it. Renge (Lotus Flower) of Myoho Renge Kyo also shows that cause and effect exists simultaneously as the Lotus Flower contains the seed or potential of the Lotus itself.

In this Sahā world it is difficult to eliminate earthly desires completely. Even so, we learn from our mistakes while we are living in the Sahā World full of suffering. We merge into the Original Buddha’s life, become involved in the Buddha’s life and live in the Buddha’s life. Thus, both good and evil deeds are reflected upon and can help us not to create these mistakes again. This is called Kai-ye, which re-evaluates things from the point of view of the Buddha’s enlightenment, gets them involved in the world of the Lotus Sūtra and finds the value of the things. As a result, everything is unified with the Lotus Sūtra and becomes an object of appreciation and respect.

A kalpa is a time period which can be defined most clearly through metaphor. Suppose there is a huge rock extending 100 miles on every side. Every 100 years a heavenly maiden comes down to the earth, rubs the rock once with the soft sleeve of her dress, then flies back to heaven. Another hundred years later, she does the same and repeats this journey every one hundred years until the rock disappears. The length of time necessary to cause the rock to disappear is a kalpa. It is extremely long period of time. In pre-Lotus Sutra teachings, one could attain Buddhahood by means of “Ryakkō-shugyō,” practice for many kalpas.

When we have joy, we should realize that true joy is to live along with the Buddha. We should practice harder and not wallow in earthly pleasures. We can make earthly pleasure a starting point for true joy.

Thus, while living in this world with suffering and joy, we live along with the Buddha and Nichiren Shōnin. Living with religious joy rising out of the suffering and joy in this world is called Jiju Hōraku; this is receiving joy of the Dharma by oneself. As we are living in this defiled world of reality with our defiled bodies, we are living along with the Buddha in this Pure Land. It is this joy of faith that is the resolution of our sufferings.

Nichiren Shōnin stated in Kanjin Honzon Shō,

Śākyamuni 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 characters of Myo, Ho, Ren, Ge and Kyo 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.”
(WNS2, p. 146)

These two merits are called Ingyō and Katoku.