The more we live accorcing to the Word, the more we are motivated by real goodness. Our actions begin to become spiritual in quality, because the spiritual level of our internal mind is opened. If this happens, our natural mind will be opened at the top, so that what exists at the spiritual level of the mind (charity or love toward the neighbor) could flow down into our conscious mind and move us in our everyday lives.
However, above the spiritual level of our mind is the celestial level. If we were to go on living a life of charity for the rest of our lives, we would indeed become heavenly, but we would never rise above that middle spiritual level. To go beyond that, we need to come into celestial love–loving the Lord (or rather, having his love come into us). We accomplish that by obeying the Lord’s commandments for his sake rather than any selfish thought of promoting ourselves. In that way, love and concern for the Lord flow down into our natural mind, making it celestial or spiritual in quality (see Divine Love and Wisdom, Section 237).
Because we have free will, we can also choose to keep our natural mind closed at the top, so that none of these higher loves can flow in. That happens to the extent that we do not live according to what the Word of God teaches us to believe and do. In that case, we would remain the same forever, even in the spiritual world, and never be able to experience heaven’s love.
In summary, regeneration or rebirth consists in allowing the higher levels of our mind to act upon our natural level, transforming it and making it spiritual or celestial in quality. (There is a fuller explanation of regeneration in chapter 2.) However, these levels do not simply merge one into the other; they remain distinctly separate, which is the idea behind the concept of “discrete degrees” discussed above. These levels remain distinct from the brain and the body where it lives.
from The Hidden Levels of the Mind, Swedenborg’s Theory of Consciouseness by Douglas Taylor