The Bible uses various metaphors to describe the propensity for evil in human nature.
And the Lord said unto Cain, “Why art thou wroth? and why is thy countenance fallen? If thou doest well, shalt thou not be accepted? and if thou doest not well, sin lieth at the door. And unto thee shall be his desire, and thou shalt rule over him.” And Cain talked with Abel his brother: and it came to pass, when they were in the field, that Cain rose up against Abel his brother, and slew him. -Genesis 4:6-8
Knowing this, that our old man is crucified with him, that the body of sin might be destroyed, that henceforth we should not serve sin. -Romans 6:6
Dearly beloved, I beseech you as strangers and pilgrims, abstain from fleshly lusts, which war against the soul -1 Peter 2:11
Carl Jung postulated the existence of a “shadow self” as an aspect of our personality. He argued that the path to wholeness lies in integrating this dark, unconscious side of one’s personality into one’s conscious thoughts and actions. Various works of fiction have employed this motif, whether before or after the work of Jung. One such modern example is Ursula Leguin’s A Wizard of Earthsea, which also draws on feminist themes and concepts from eastern philosophy and spirituality.
Christians should be wary of such concepts, which find ways of influencing the zeitgeist of our societies. The quotation from 1 Peter above tells Christians not to incorporate the shadow self into our lives, but to resist its evil impulses and seductions. St Paul, drawing on Christ’s own teachings, articulated an anthropology in which the evil side of our character was a thing to be crucified, that had been crucified with Christ and would be purged from us in the resurrection.
Following Christ’s teaching means renouncing and executing this side of ourselves on a daily basis, Lent being a season of the liturgical year that focusses on this doctrine, drawing inspiration from the Temptation of Christ in the wilderness. The Temptation is presented in detail in Matthew 4 and Luke 4. Milton wrote about the Temptation in his lesser known Paradise Regained.
The shadow in our hearts can also lead to madness. Today we see great fits of madness in the outbursts of individuals and in the actions of groups. While Christianity involves a mystical side and acceptance of the fact that we do not know everything, it is not a call to insanity, to the submersion of our rational minds. We are to use our minds to contemplate truth and to preach truth to others and live it by example. This “way of truth” is another aspect of the daily call to “take up one’s cross” as discussed above. We are in a war over Truth with a capital T. An important aspect of these end times is the spread of deception and madness.
The discipline of the Lenten season, then, is about the mind and the body. Let us not be blind to evil, to the work of the fallen nature, of the world, and of the Devil. He wants to sit on the throne of God, not just in Jerusalem, but in our hearts.
O my God, I cry by day, but you do not answer, and by night, but I find no rest. Yet you are holy, enthroned on the praises of Israel. In you our fathers trusted; they trusted, and you delivered them. -Psalm 22:2-4