The oneness of [spiritual] warmth and light (that is, of the spiritual [energy] that emanates from the Lord as the sun) can be illustrated by the warmth and light that emanate from the sun of our physical world. These “two” are also a single whole as they radiate from the sun. The reason they are not a single whole on earth is to be found in the earth itself, not in the sun. The earth rotates daily on its axis and follows its annual ecliptic orbit. This is why its warmth and light do not seem to be a single whole, why there is more warmth than light in midsummer and more light than warmth in midwinter. The same thing happens in the spiritual world. While the earth there does not rotate or follow an orbit, angels do turn more and less toward the Lord. The ones who turn more toward him accept more of the warmth and less of the light; while the ones who turn less toward the Lord accept more of the light and less of the warmth. This is why the heavens, which are made up of angels, are marked off into two kingdoms, one called “heavenly” and the other called “spiritual.” Heavenly angels accept more of the warmth and spiritual angels accept more of the light.
The regions where angels live also look different depending on their acceptance of the warmth and light. The correspondence is exact, provided we think of angels’ change of state instead of earthly motion.
We will see later [Section 124] that in their own right, all the spiritual phenomena that stem from the warmth and light of their sun constitute a single whole in the same way, though they do not do so if we regard them as coming from the feelings that angels have. When the warmth and light are a single whole in the heavens, it is like The spiritual warmth and light that result from the emanation from the Lord as the sun form a single whole just as his divine love and wisdom do.. When they are not a single whole, it is like either summer or winter—not like winter in cold latitudes but like winter in warm latitudes. The essence of angelic nature is a balanced acceptance of love and wisdom, so angels are angels of heaven depending on the oneness of their love and wisdom. The same holds true for us of the church, if our love and wisdom, or charity and faith, are fully united.
from Divine Love and Wisdom, Sections 101, 102