Since angels have no concept derived from time, as we in our world do, they have no concept of time or of the things that depend on time. They do not even know what all these temporal things are, like a year, a month, a week, a day, an hour, today, tomorrow, or yesterday. When angels hear these expressions from one of us (angels are always kept in contact with us by the Lord), they perceive states instead, and things that have to do with state. So our natural concept is changed into a spiritual concept with the angels. This is why expressions of time in the Word mean states, and why things proper to time like the ones listed above mean the spiritual things that correspond to them.
It is much the same for all the things that occur as a result of time, such as the four seasons of the year called spring, summer, autumn, and winter; the four times of day called morning, noon, evening, and night; our own four ages called infancy, youth, maturity, and old age; and with the other things that either occur as a result of time or happen in temporal sequence. When we think about them, it is from a temporal standpoint; but an angel thinks about them from the standpoint of state.
Consequently, anything in them that is temporal for us changes into an idea of state for the angel. Spring and morning change into an idea of love and wisdom the way they are for angels in their first state; summer and noon change into an idea of love and wisdom as they are in the second state; autumn and evening, as they are in the third state; and night and winter into a concept of the kind of state that is characteristic in hell. This is why similar things are meant by these times in the Word. We can see from this how the natural concepts that occur in our thought become spiritual for the angels who are with us.
Since angels have no notion of time, they have a different concept of eternity than we earthly people do. By “eternity,” angels perceive an infinite state, not an infinite time.
I was thinking about eternity once, and using a concept of time I could grasp what “to eternity” entailed—namely, without end—but not what “from eternity” entailed and therefore not what God did before creation, from eternity. As my anxiety mounted because of this, I was raised into the sphere of heaven and therefore into the perception of eternity shared by angels. This shed light for me on the fact that we ought not to think about eternity in temporal terms but in terms of state, and that when we do, we can grasp what “from eternity” entails, which was actually done for me.
from The Lives of Angels