In people, the Infinite Divine is present the way something is present in an image of itself. The Word shows this, when we read the following:
Finally God said, “Let us make human beings in our image, according to our likeness.” Therefore God created human beings in his own image; in the image of God he created them. (Genesis 1:26–27)
From this statement it follows that human beings are organisms that are open to God, and organisms whose quality depends on their response.
The human mind—the source and determiner of our humanness—has been formed into three areas to match three levels. On the first level the human mind is heavenly; angels of the highest heaven are on that level. On the second level it is spiritual; angels of the middle heaven are on that level. On the third level it is earthly; angels of the lowest heaven are on that level.
Organized as it is to accommodate these three levels, the human mind is a vessel for receiving divine inflow. Yet what is divine does not flow in beyond our smoothing of the way [Isaiah 40:4] or our opening of the door [Revelation 3:20]. If we smooth the way and open the door all the way to the highest level, the heavenly one, then we truly become an image of God. After death we will become an angel of the highest heaven. If we smooth the way or open the door only to the middle or spiritual level, then we still become an image of God, but one that is not as complete. After death we will become angels of the middle heaven. But if we smooth the way or open the door only to the lowest or earthly level, then we become an image of God at the lowest level, provided we acknowledge God and worship him with acts of devotion. After death we will become angels of the lowest heaven.
If we do not acknowledge God and do not worship him with acts of devotion, we divest ourselves of the image of God and become like one type of animal or another, except for the fact that we still enjoy the ability to understand and therefore to speak. If under those circumstances we close our highest earthly level, which corresponds to the highest heavenly level, we become like farm animals in what we love. If we close our middle earthly level, which corresponds to the middle spiritual level, we become like foxes in what we love, and like birds that come out in the evening, as far as our intellectual discernment goes. If we close even our lowest earthly level to its spiritual counterpart, we become like wild animals in what we love and like fish in our understanding of truth.
Divine life flows in from the sun of the angelic heaven and energizes us much the way light from our sun flows into a transparent object. Our highest level receives life the way light flows into a diamond; our second level receives life the way light flows into a crystal; our lowest level receives life the way light flows into translucent glass or parchment.
If the lowest degree is totally closed spiritually, as happens when we deny the existence of God and worship Satan, life flows into us from God much the way light flows into opaque things on earth: rotten wood, swamp sod, dung, and so on. At that stage we become spiritual cadavers.
from True Christianity, Volume 1, Section 34