Because the Buddha’s life and heart exist without regard to time and space, his capacity for compassion and wisdom are equally as endless. We humans often have small hearts and lives and perhaps cannot imagine ever having as great a capacity for compassion and wisdom as the Buddha. We may never be able to conceive of living without hate, jealousy or anger. Through our connection with the Buddha, however, we can develop such a capacity for compassion and wisdom as well as connection with all living beings.

With the Odaimoku of Namu Myoho Renge Kyo the Buddha’s virtue of Ichinen Sanzen is transferred to us naturally. It is the Buddha’s way to save living beings in Mappō. Nichiren Shōnin understood this through his faith. It is the virtue of the Odaimoku left by the Buddha for those who are in Mappō. It is the Buddha’s ultimate compassion.

[A]s we receive the merits from the Buddha, the Great Mandala and the Odaimoku by devoting ourselves to them, we also send merits to them as well. How wonderful it is!
Our participation in the Buddha’s activities are also the activities of the Buddha residing in us and the activities of the nine realms residing in the Buddha’s life. This is the mutual possession of ten realms, Jikkai Gogu, and true cause and true effect, Hon-in Hon-ga. In other words, cause-and-effect, the realm of Buddha and the other nine realms are existing simultaneously and in oneness. Nichiren Shōnin stated in Kanjin
Honzon-Shō,

“All those who receive His (the Buddha) guidance are one with this Eternal Buddha,” (WNS2).

We are a part of the great life of the Eternal Buddha who has existed with the nine realms since the beginningless beginning.

Śākyamuni Buddha has neither beginning nor end and has overcome birth, aging, sickness, and death upon his enlightenment. He has risen above life and death and thus, his own life had no birth or death. The Buddha has also gone beyond [or outside of the bounds of] linear time. The ability to recall his own previous existences is indicative of this capacity. To exist without the limits of time and space indicates that the Buddha’s life is everywhere and nowhere; essentially, his life is the entire universe. To understand these ideas, one needs to abandon the notion of time as a linear concept, and enlarge one’s thinking to conceive of time as a multi-dimensional concept, almost layered in nature. The Buddha often speaks of time as if past, present, and future existed simultaneously in different realms as well as in different world systems.

Grand Master T’ien-tai awakened to Ichinen Sanzen by practicing spiritual contemplation and insight. He may have meditated while thinking something like, “I was born from my parents. If my parents did not exist, I wouldn’t have existed. In other words, my parents are living in my life. If I trace back my family, there are immeasurable lives living in myself. Not only that but also I have been taken care by innumerable people since I was born. The meals that I ate today are great merits of many farmers’ hard labor. Because of those people, I am able to live my life today. In other words, the lives of those people also exist in my life. We are living in the world based on the culture that was created by people in the past. It means that people in the past who created the culture also live in my life. Not only human but also because of nature such as grass and trees, water and air, and the sun and land, my life has been maintained. However, people in Mappō do not have the same ability as T’ien-tai to awaken to Ichinen Sanzen. Attaining Buddhahood is limited only with Ichinen Sanzen. Following this logic, we wouldn’t be able to attain Buddhahood. With this point as his ultimate conclusion, Säkyamuni Buddha offered us the Odaimoku with his great compassion.

[When speaking of 3,000 realms, w]hat does this number three thousand represent? It represents everything not only of the earth, but also of the universe and includes everything in the past, present, and future. Everything of the universe from animals, plants, other beings, visible or invisible, and their activities, workings, and movements are included in the three thousand realms. Everything of the universe exists within each one of us. Everything influences us, works together as primary cause and environmental cause and brings effects, rewards and retributions. All of us exist in relationship with everything in the universe.

“Equality as such” means that every one of the ten suchnesses is not separate from each other. They are always contained in one body in relationship to each other. The idea of ten suchnesses applies not only to human beings but also to all things, mind, or even life after death. The ten suchnesses exist in all one hundred realms. … Each realm of the one hundred has its own ten suchnesses such as appearance, nature, entity, power and so forth. In other words, one hundred realms multiplied by the ten suchnesses create one thousand suchnesses.

Human beings can experience the heart of compassion like a Buddha or a Bodhisattva. We also experience anger (asura), greed (hungry spirit), or mercilessness (animal), or sink into the bottom of sufferings (hell).

“Anger represents hells; greed—hungry spirits; ignorance—beasts; flattery—asura demons; delight—gods; and calm—men.” (Kanjin Honzon- Shö, WNS2, p. 134)

“The ‘mutual possession of ten realms’ doctrine is as difficult to maintain as it is to see fire in a rock and flowers in wood. However, it is not totally impossible because rocks spark when struck together and a tree blooms in spring.” (Kanjin Honzon-Shö, WNS2, p. 136)

The Ten Suchnesses (Jū-Nyoze) appear in Chapter 2 (Expedient Means) of the Lotus Sutra (Murano, p. 24). This is the portion of the Lotus Sūtra we recite as part of our daily services and which is repeated three times during Hōben-pon. … The Ten Suchnesses are:

• Nyoze-sō, or appearance as such,
• Nyoze-Shō, or natures as such,
• Nyoze-tai, or entities as such,
• Nyoze-riki, or powers as such,
• Nyoze-sa, or activities as such,
• Nyoze-in, or primary causes as such,
• Nyoze-en, or environmental causes as such,
• Nyoze-ka, or effects as such,
• Nyoze-hō, or rewards and retributions as such,
• Nyoze-honmatsu-kukyō-tō, or equality as such despite these differences.

The mutual possession of the ten realms (Jikkai-gogu) means that each of the ten realms of living existence contains the characteristics of the other nine realms. The realm of hell to the realm of heavenly beings are known as the “Six Regions” which are the realms of transmigration (rebirth) one reaches according to karma, or the deeds of one’s previous lives. The realm of Srāvaka to the realm of Buddhahood are the realms of “the four holy ones” or those who transcend the cycle of transmigration.

“Spiritual contemplation (kanjin) means for one to meditate on his own mind, observing through it ten realms, from the hells up to the realm of Buddhas, all of which are by nature contained in every mind.” (Kanjin Honzon Shō, WNS2, p. 131).