The idea that every person's soul simultaneously harbors both an angel and a demon in the form of a snake symbolizes an inner duality—a constant struggle between the aspiration for the sublime and good, and the temptation that leads to moral ruin.

The Inner Battle of Light and Darkness

The idea that every person's soul simultaneously harbors both an angel and a demon in the form of a snake symbolizes an inner duality—a constant struggle between the aspiration for the sublime and good, and the temptation that leads to moral ruin. This is not merely a figurative comparison, but a metaphor reflecting how a person is continuously tested through inner thoughts and actions, and how their moral state depends on which side they choose.

For example, one source asserts:
"Had we been able to see our own soul, we would have marveled and been terrified: in our soul exists both the light of paradise and the black flame of hell. Our soul is like a wondrous celestial flower, yet a flower covered with poisonous spiders. Our soul resembles a beautiful, uncreated temple in the glory of the Almighty God, yet along the steps of this temple crawl terrible snakes... Angels pray for our soul, the heavens rejoice when we repent of our sins. Thus, the human soul is so precious before God, more precious than all created things! But a demon approaches and sings to it a serpentine infernal song, and, enchanted by its tempter, it most often follows him—to its own doom."
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In this excerpt, the image of the angel symbolizes purity, repentance, and the divine presence that safeguards the soul and guides it on the path of righteousness. On the other hand, the demon, associated with the snake, represents temptation, seduction, and the eternal struggle that can lead the soul to ruin if resistance is not met.

This notion is closely related to the concept of moral testing, as every person faces a daily choice between good and evil. In another source it is emphasized that "each person consists of two parts that oppose one another"—an angel that directs towards true virtues and a demon that leads to sinful thoughts, temptations, and moral decay. This division demonstrates that the inner battle is inseparable from the moral trial, forcing one to continuously "fight" against their own vices and temptations.

Thus, the idea of the presence in the soul of both an angel and a demon in the form of a snake underscores that each person is constantly challenged in the strength of their morality: the choice between light (from the angel) and darkness (from the demon) determines their spiritual state and the direction of their life. This trial is an inherent part of human nature, where willpower and conscious decision play a decisive role in achieving inner harmony and moral purity.

Supporting citation(s):
"Had we been able to see our own soul, we would have marveled and been terrified: in our soul exists both the light of paradise and the black flame of hell. Our soul is like a wondrous celestial flower, yet a flower covered with poisonous spiders. Our soul resembles a beautiful, uncreated temple in the glory of the Almighty God, yet along the steps of this temple crawl terrible snakes... Angels pray for our soul, the heavens rejoice when we repent of our sins. Thus, the human soul is so precious before God, more precious than all created things! But a demon approaches and sings to it a serpentine infernal song, and, enchanted by its tempter, it most often follows him—to its own doom." (source: link txt)

"Grigory. Aatixajv or Daimon, meaning the spirit of vision. Each person consists of two parts that oppose one another and battle—those of the noble and the base, in other words, of eternity and decay. Therefore, each individual harbors two demons or angels, that is, the heralds and messengers of their respective rulers: the good and the evil angel, the protector and the destroyer, the peaceful and the rebellious, the bright and the dark... Overcome, my friend, your inner self..." (source: link txt)