Given this kind of difference between the warmth and light of the two worlds, it is obvious why people who live in one of the worlds cannot see people who are living in the other. Our eyes, which see in physical light, are made of substances of their own world, and angels’ are made of substances of their world. In other words, in each case they are designed for adequate sensitivity to their own light.
We can see from this what ignorance underlies the thinking of people who exclude from their faith any notion that angels and spirits are people, simply because they do not see them with their own eyes.
It has not been known before that angels and spirits are in a completely different light and warmth than we are. It has not even been known that there was a different light and warmth. Human thought has not penetrated beyond the deeper or purer aspects of nature. As a result, many people have located the dwellings of angels and spirits in the ether or even in the stars—within nature, that is, and not above or beyond it. In fact, though, angels and spirits are wholly above or beyond nature. They are in their own world, one that is under a different sun. Further, since spatial intervals are only apparent in that world, as I have explained earlier [Section 7], we cannot say that they are in the ether or in the stars. They are right with us, united to our own spirits in feeling and thought. Each of us is a spirit. That is the source of our thinking and intending. This means that the spiritual world is right where we are, not distanced from us in the least. In short, as far as the deeper levels of our minds are concerned we are all in that world, surrounded by angels and spirits there. We think because of the light of that world and love because of its warmth.
from Divine Love and Wisdom, Sections 91, 92
Section 7: Published 4/10/2018