This was originally part of an answer I wrote to someone who found the concept of the three bodies of the Buddha confusing.

My preference in regard to all things that appear confusing is to recall the number of times people ask questions in the Lotus Sutra. The whole purpose of the pursuit of Enlightenment is to gain the wisdom of the Buddha. Asking questions fits right in. And when there is no one to ask, I find just contemplating the question can allow me to relieve the anxiety of not knowing or, from a different perspective, release the attachment I have to needing to know everything.

The concept of the Three Bodies of the Buddha is important but more for contemplating than for actually knowing. I like to think of it this way. (And this is _just_ my view; nothing official, nothing enlightened.) The historical Buddha sat under the Bodhi tree and became enlightened. What he became enlightened to existed already much as we might say Newton discovered gravity. No one would suggest he created gravity. That pre-existing, always existing Enlightenment is one of the Buddha’s bodies in the Nichiren Shu tradition.

This concept of what it means to become enlightened is alluded to in Chapter 7 of the Lotus Sutra, The Parable of a Magic City:

The Buddha said to the bhiksus:
The duration of the life of Great-Universal-Wisdom-Excellence Buddha was five hundred and forty billion nayuta kalpas. [Before he attained Buddhahood,] he sat at the place of enlightenment and defeated the army of Mara. He wished to attain Anuttara-samyak-­sambodhi, but could not because the Dharma of the Buddhas had not yet come into his mind. He sat cross-legged without moving his mind and body for one to ten small kalpas. During all that time the Dharma of the Buddhas did not come into his mind.

I personally love the line, “the Dharma of the Buddhas did not come into his mind.” Keep trying.

Sakyamuni’s enlightenment of itself is another body. The physical body that existed in time and space is the third.

Lots of resources for Nichiren Shu doctrine are available in English. I have a personal blog — 500yojanas.org — and that includes books I’ve read and some quotes from each that I found inspiring. I strongly recommend subscribing to the Daily Dharma, which is an email list. I collect these daily emails on my website and often use them as part of my personal practice.

Here I’ll close by throwing out a couple of those quotes to consider.

From Lotus Seeds: The Essence of Nichiren Shu Buddhism:

Shakyamuni Buddha was no different than any of us, except for his extraordinary wisdom and compassion. He is known as “the” Buddha, not because he attained something that ordinary people cannot attain, but because he was the first person in recorded history to awaken to the truth and to show others how to do so. In that sense, the title “Buddha” is reserved for Shakyamuni simply because he happened to be the one to fulfill the role of teacher and model for all those who would follow his path. However, all of us have the Buddha-nature. Therefore, all of us are capable of displaying the same wisdom and compassion as Shakyamuni Buddha.

From Odaimoku: The Significance Of Chanting Namu Myoho Renge Kyo:

By embracing the faith and practice of Myoho Renge Kyo, we can revitalize our lives. In other words, regardless of the state of life in which we find ourselves at any given moment, through faith and practice we can transform any life condition (no matter how negative) into enlightenment. In this way, we can develop wisdom and a life that is no longer a slave to pain, delusion and suffering.

Again, this is _just_ my view; nothing official, nothing enlightened.