1. The Spirit World Corresponds to the Physical World

World Scripture

I [Paul] know a man in Christ who fourteen years ago was caught up to the third heaven— whether in the body or out of the body I do not know, God knows. And I know that this man was caught up into Paradise—whether in the body or out of the body I do not know, God knows—and he heard things that cannot be told, which man may not utter.
2 Corinthians 12.2-4

No one in heaven or on the earth knows the Unseen save God; and they know not when they will be raised. Does [human] knowledge extend to the Hereafter? No, for they are in doubt concerning it. No, for they cannot see it.
Qur’an 27.65-66

God created the seven heavens in harmony. Qur’an 71.15 What is here [the phenomenal world], the same is there [in Brahman]; and what is there, the same is here.
Katha Upanishad 2.1.10 (Hinduism)

Thou who exists beyond the wide firmament, mighty in Thine own splendor and strong of mind, hast made, for our help, the earth a replica of Thy glory.
Rig Veda 1.52.12 (Hinduism)

We have such a high priest, one who is seated at the right hand of the throne of the Majesty in heaven, a minister in the sanctuary and the true tabernacle which is set up not by man but by the Lord… There are priests who offer gifts according to the law. They serve a copy and shadow of the heavenly sanctuary; for when Moses was about to erect the tabernacle, he was instructed by God, saying, “See that you make everything according to the pattern which was shown to you on the mountain.”¹
1 Hebrews 8.1-5

The system of Change is tantamount to Heaven and Earth, and therefore can always handle and adjust the way of Heaven and Earth. Looking up, we observe the pattern of the heavens; looking down, we examine the order of the earth. Thus we know the causes of what is hidden and what is manifest. If we investigate the cycle of things, we shall understand the concepts of life and death. Essence and material force are combined to become things. The wandering away of Spirit becomes change.
From this we know that the characteristics and conditions of spiritual beings are similar to those of Heaven and Earth and therefore there is no disagreement between them. The knowledge [of Spirit] embraces all things and its way helps all under heaven, and therefore there is no mistake. It operates freely and does not go off course. It rejoices in Nature and understands destiny. Therefore there is no worry. As [things] are contented in their stations and earnest in practicing kindness, there can be love.
It molds and encompasses all transformations of Heaven and Earth without mistake, and it stoops to bring things into completion without missing any.
I Ching, Great Commentary 1.4.1-4 (Confucianism)

To fear death, gentlemen, is no other than to think oneself wise when one is not, to think one knows what one does not know. No one knows whether death may not be the greatest of all blessings for a man, yet men fear it as if they knew that it is the greatest of evils. And surely it is the most blameworthy ignorance to believe that one knows what one does not know.
Socrates, in Plato, Apology 29 (Hellenism)

Teachings of Sun Myung Moon

Human life does not end with the death of the physical body. It continues in the spirit world, where saints and sages and also all of our ancestors live as spirit selves. It is a form of human existence of a higher order than in life in the physical body. This earthly world where our physical bodies dwell is only a minuscule part of the infinite and eternal world—the fundamental world that God created.
(July 10, 2003)

You should clearly know God and the spirit world. Even if fallen people forget about everything else, they should know these two well. The [heavenly] spirit world is the eternal fatherland, our eternal original home. However, we cannot establish this original home once we arrive at the spirit world; we must do it while on earth.
(398:145, December 9, 2002)

Do you know that the Bible mentions the third heaven? Saint Paul saw it fourteen years before [he wrote the epistle]. During those fourteen years, Paul built himself up, holding onto his experience of seeing the third heaven. Paul not only talked about the third heaven; he could keep going because he had glimpsed a realm higher than the world around him.
(62:47, September 10, 1972)

The spirit world is connected with the physical world. The focal point and common factor linking them is true love.
(137:54, December 18, 1985)

The quality of your internal life on earth will be visible in the spirit world. Love is central, because the love within God and human beings joins them like the cells of the body. In the spirit world we each become one of the cells. Once you enter that dimension, God will surely come inside your heart. When you call, “God!” He will answer in your heart, “Who is calling me? What do you want?”
(218:129, July 14, 1991)

Where is the spirit world? Is it outside your body, or does it come inside your body? It penetrates even inside your body. You are walking around with the spirit world on your shoulders; you are carrying it and holding it wherever you go. Can you get away from it? Impossible. That is why my heart is always confident wherever I go, and why opposition cannot affect me.
(162:116, March 30, 1987)