It's a fact that it's an invisible entity, so there's no way to prove it.
From here on, it's my personal interpretation.
There is a saying “the three bodies of the Buddha.”
It means there are three bodies.
There are three: hosshin (hosshin), return (hojin), and ojin (ojin).
The corporation is all of that, all of the world. One existence. The phrase “three bodies is one body” indicates that they all exist the same thing. empty.
Retaliation is an invisible presence. An invisible world. There is no body. (Spiritual body? etc.) The other world. Among them, Nyorai attains enlightenment and does not require reincarnation. (Spirit, Shinga, Nyorai, Brahman, etc.)
Response exists just like us. The visible world. A being with a physical body. this world. Among them, Bodhisattvas are beings who have come to save us from another world. (Human, Ego, Bodhisattva, Atman, etc.)
I think people who know probably understood its existence, and the world.
Therefore, they named their existence and personified it.
I think there are a lot of Buddhas now.
Hosshin Buddha (Hosshinbutsu) — the principle of the great universe, the truth, the Buddha personifies the source of light energy that is pervasive throughout the universe, has no shape or shape, and is just there. In Exoteric Buddhism, it is named Birushana Buddha, and in Esoteric Buddhism, it is named Dainichi Nyorai.
Hojinbutsu (Hojinbutsu) — An incarnate Buddha where the wisdom, light, love, and mercy of Doshinbutsu are revealed as kashinbutsu. The Buddha showed the many powers and functions of Doshinbutsu separately. There are many people, such as Amida Nyorai and Yakushi Nyorai.
Ojinbutsu (Ojinbutsu) — An alter ego Buddha who has adapted to save sentient beings, and has incarnated his alter ego as a human in this world. There are Shakyamuni Nyorai, Miroku Bosatsu, etc. It is the alter ego of Hoshin Buddha, where all humans can also become Oshinbutsu if they understand it.
Please bear with me that this is just my personal opinion.
There are various theories.
Finally, read Buddhism, like the handwriting, is the Buddha's teaching, so the most important thing is to put the teachings into practice. Even if you study, it's nothing without practice.
Ryoei Gasho