The question arises as to how we should consider the doctrine of the Three Thousand Realms in One Mind. When we understand this doctrine only theoretically, it cannot generate the power capable of saving others as well as ourselves. This is called the theoretical doctrine of the Three Thousand Realms in One Mind (ri no ichinen-sanzen). Far from saving others, we are unconsciously enslaved by the philosophical theory of the doctrine and eventually may become so obsessed with the thought of the myriad implications of our every act that we become mentally paralyzed, as it were. We must accept this doctrine with an open-hearted, optimistic, and positive attitude.

The doctrine of the Three Thousand Realms in One Mind teaches us that we have the infinite possibility of moving both upward and downward. If we resolve firmly to practice the Buddha’s teachings, we can go upward without fail. Secondly, this doctrine lets us realize clearly that in all the universe, there is no individual existing apart from the whole and that all things are interconnected like the meshes of a net. Individual salvation alone is not true salvation.

When we understand these two teachings not only theoretically but also in the depths of our hearts, we cannot help elevating ourselves and practicing in order to help others. This is called the practical doctrine of the Three Thousand Realms in One Mind (ji no ichinen-sanzen). Unless we thoroughly understand the doctrine of the Three Thousand Realms in One Mind in this way, it does not become a living doctrine.

Nichiren spoke in the highest terms of the doctrine of the Three Thousand Realms in One Mind. He derived his teachings from this doctrine, but ultimately he passed beyond a theoretical understanding and realized that for Buddhists the doctrine should result in faith and practice. Indeed, if we can thoroughly understand the theoretical doctrine, we should awaken to the fact that we must be concerned as long as there is a single person in the world who is suffering. Unlike the worries of an ordinary man, this is a great worry, the Buddha’s worry. This is the meaning of the expression, “When living beings are taken ill, the Buddha suffers pain.” It is also the significance of Nichiren’s words, “Although Nichiren does not weep in reality, tears of worry for others always flow from his eyes.”

If we must be worried about something, we should have the same worry as the Buddha and Nichiren. Such a worry gives us courage and makes us find life worth living. After all is said and done, there is no work that is more valuable in this world than to save people who are suffering. To elevate human beings is the loftiest work. Our own consciousness of having taken part in this work, small as we are — this consciousness alone should brighten our lives.