Repentance becomes effective if we practice it regularly—that is, every time we prepare ourselves to take the Communion of the Holy Supper. Afterward, if we abstain from one sin or another that we have discovered in ourselves, this is enough to make our repentance real. When we reach this point, we are on the pathway to heaven, because we then begin to turn from an earthly person into a spiritual person and to be born anew with the help of the Lord.
This change can be illustrated by the following comparison. Before repentance, we are like a desert, inhabited by terrifying wild creatures, dragons, eagle-owls, screech owls, vipers, and bloodletting snakes; in the clumps of bushes in that desert there are the owls and vultures [mentioned in the Bible], and satyrs are dancing [Isaiah 13:21]. After these creatures have been expelled by human work and effort, however, that desert can be plowed and cultivated into fields, and these can be planted with oats, beans, and flax, and later on with barley and wheat.
This can also be compared to the wickedness that is abundant and dominant in humankind. If evildoers were not chastised and punished with whippings and death, no city would survive; no nation would last. In effect, each one of us is society itself in its smallest form. If we do not treat ourselves in a spiritual way as evildoers are treated by the larger society in an earthly way, we are going to be chastised and punished after death; and this will continue until out of sheer fear of further punishment we stop doing evil, even if we can never be compelled to do what is good out of love for it.
from Regeneration, Pages 32, 33