Human nature, defined as the fundamental dispositions and characteristics of human beings, is highly susceptible to corruption. We tend to be selfish, self-centered, and self-aggrandizing, habitually following behaviors and opportunities that promote or benefit us without thought to how they may affect others. Everyone covets what others have, most will lie to deflect hurt or blame, some will steal to line their pockets, and a few will take another person's life to protect their self-interests. Originally, the nature God created in man was very good, not corrupt. When created, Adam and Eve had pure minds, though as fleshly beings, they had physical drives that tend to pull in a selfish direction, such as drives to feed and protect themselves. They were innocent in their pursuit to satisfy these drives. However, their idyllic life ended with the temptation by the cunning serpent, who sowed doubt and confusion in Eve's mind, accused God of deceit, and urged her to desire equality with God through disobedience. Eve ate of the forbidden fruit, and Adam weakly followed her lead into sin. In this moment, carnal human nature, which all human beings now possess, was created. This nature generally follows the course it took with Eve: the forbidden fruit looked good, she desired to eat it, and saw how it could benefit her, so she partook of it despite God's command. Because of their rebellion, God let humanity go its own way, giving them over to a debased mind to do things which are not fitting. Now all of humanity, except for those few whom God calls to redeem, are open to the selfish and rebellious attitudes broadcast by the adversary, and without resistance, all fall under its influence, making it their nature as they grow up.

Carnal human nature arises because the whole world lies under the sway of the wicked one, whose spirit actively works in the sons of disobedience. This influence shapes every person so that all once walked according to the course of this world, conducted themselves in the lusts of the flesh, fulfilled the desires of the flesh and of the mind, and were by nature children of wrath. God did not create this nature; the enemy did, and the resulting spirit turns people inward toward extremes of self-centeredness while simultaneously moving them against trust in God. The process begins subtly, as shown when the serpent entered the garden environment and quickly undermined divine influence, leading Adam and Eve to submit. The same pattern continues today through the surrounding culture, where attitudes, character, and conduct pass readily from one person to another, especially among the immature. Visual imagery, words, and music intensify the effect, requiring deliberate spiritual resistance. A protective hedge can be removed when carelessness allows the barriers to be breached, permitting immorality to increase rapidly in the environment. The outcome is that carnal nature becomes the default response unless the mind remains alert to the constant, pervasive presence of the opposing spirit.

The most formidable and ever-present obstacle hindering progress toward the Kingdom of God is the flesh human nature that remains following baptism. It constitutes the major component of the cross Christians must bear while following Christ. Paul states plainly that the carnal mind is enmity against God, for it is not subject to the law of God, nor indeed can be. This nature remains constantly present and exerts a continuous drag on progress toward conforming to the image of Jesus Christ, requiring an attitude of total warfare in which the flesh must be crucified and put to death. The people of the land in Canaan serve as the primary symbol of this human nature, which cannot be made subject to God and His law. Just as those inhabitants could not be removed without divine intervention, carnal nature cannot be overcome apart from God's help. The promises in Exodus 23 guarantee that God will drive out such enemies and deliver them into His people's hands, yet the explicit command remains that the Israelites must drive them out before themselves. This arrangement establishes a cooperative effort in which God intervenes to make success possible while requiring active participation from His people. Israel's wilderness experiences demonstrate the consequences of failing to engage this fight. The spies' fear at the border revealed a lack of trust that God would cooperate in the warfare, leading the nation to draw back from the required confrontation. Their refusal to proceed illustrated how carnal tendencies produce rebellion when left unchecked. God tests His people to reveal the condition of their hearts and to expose weaknesses, designing each path to require battle at the level of individual ability. This pattern connects directly to the broader message of sanctification under the New Covenant. Reciprocity characterizes the relationship with God, as love and obedience cannot remain one-sided. Christians must therefore fight the good fight of faith, expecting resistance from carnal nature while relying on divine promises of assistance. Without such engagement, the law cannot be written in the heart, and preparation for the Kingdom cannot occur.