Human beings are born morally neutral, a blank slate, but because we are clothed in flesh with its needs and desires, we tend toward self-satisfaction and selfishness. Childhood trains us to have our fleshly desires met, so by the time we reason, human nature is already pulling us toward evil. Paul teaches that carnal people sell out to evil (Romans 7:14). Jesus says plainly, "If you then, being evil..." (Matthew 7:11), using poneros, not kakos, which means active, rebellious, morally corrupt evil like Satan's. We stand at one end of the moral spectrum, and God, who is transcendently and eternally good, stands at the other. Adam and Eve took from the Tree of the Knowledge of Good and Evil, and every human except Christ has repeated that act, claiming the right to decide good and evil by trial and error. Rather than bringing wisdom, this has placed us under the curse of sin, for "all have sinned" (Romans 3:10, 23). Even converted Christians remain a mixed bag. They are called, given the Holy Spirit, and charged to move from evil to good, yet they still carry an evil-leaning nature and the baggage of past sins. The chief enemy is therefore within us. We cannot change the world's evils or Satan, who is already defeated, so we resist him by avoiding temptation, doing good, and overcoming our own inner evil. Jesus stresses that defilement comes from within (Mark 7:14-16), so the evils we must fight are those we conceive, nurture, and express from our own hearts.

The Founders of this nation held a fundamental view that human nature is depraved, a belief that shaped their creation of a republic to control it. They understood human nature as corrupt and easily corruptible, necessitating a government with separated powers and checks and balances to prevent tyranny. They believed that power corrupts, and absolute power corrupts absolutely, driving them to design a system to constrain the evil tendencies inherent in humanity. The Bible presents a dim view of man's natural character, portraying it as a mixture of good and evil, with even the good tainted by selfish motives. Human nature, originally neutral as seen in Adam and Eve, carries a bias toward self due to the flesh's desires, making it easily pulled toward evil. After their choice to follow the serpent's influence, Adam and Eve's nature shifted from being open to God to being hostile, turning toward self and becoming enmity against Him. Man's nature is described as corrupt from youth, with hearts and eyes inclined to idolatry and sin. The heart is desperately wicked, unfathomably corrupt, and beyond human understanding. Even actions perceived as right, without God's influence, end in death due to their origin in a corrupt nature. Humanity is depicted as sick with sin from head to toe, burdened by corruption, with no inherent goodness. This evil nature is shaped by absorbing sinful attitudes from the world, being receptive to satan's broadcast of his own corrupt nature, and the inherent selfishness of the flesh. These influences—society, satan, and self—must be overcome, a struggle that persists throughout life. Even with God's Spirit aiding His called-out ones, the corrupt nature remains, requiring constant battle and transformation toward His character. God does not create human nature as evil; rather, individuals shape their own natures through choices made with free will. Each person has the ability to improve or corrupt their nature, influenced either by satan's deceit or by God's guidance. Despite God's desire for humanity to choose life and love Him, the choice remains with the individual, often leading to separation from Him due to persistent sin. Throughout history, as seen from Adam and Eve onward, humanity has followed a path of corruption, with God allowing mankind to reap the consequences of their choices. Only through His calling and grace can a person change their nature, yet even then, the struggle against inherent evil persists, requiring sanctification to cleanse and transform into His image.

Despite experiencing God's forgiveness and being set on the right path, the evil nature within us, grown over many years, is not removed or fundamentally changed. It remains, influencing every decision, conscious or unconscious, ensuring the fight between human nature and God's nature continues to rage. Many newly baptized individuals are distressed by how soon they sin after baptism, for God does not take away this evil nature; we must still engage and overcome it. The poor habits, bad attitudes, wrong ideas, and ingrained behaviors built up over years linger on, making it our Christian duty to put them down daily. God declares in Jeremiah 17:9 that the heart is deceitful above all things and desperately wicked, a truth that cuts to the quick anyone with a hint of pride. Though most of us believe we are pretty good, God's words challenge us to question if we are fooling ourselves, merely conforming to peer pressure or acting for the wrong reasons. God asserts that only He truly knows our real character, for the heart deceives us most of all, leaving us to wonder if our motives have ever been good for anything. Part of the Christian life is endeavoring to realize just how corrupt our hearts actually are. The human heart, the seat of intellect, emotions, attitudes, and inclinations, is dishonest and evil. Most of us take this evil far too lightly, especially within ourselves, preferring to see ourselves as the good guys while pointing fingers at others. Such self-justification can lead to sins like self-righteousness, pride, and sloth in overcoming and growing, potentially manifesting in active rebellion against God. If we think we have nothing more to change or repent of, our growth will slow and stop, leading us away from God, the exact opposite of what He seeks in His children.

Evil nature resides within every human being as an inherent tendency toward rebellion against God and moral deficiency that harms self and others. This nature is not neutral but inclines toward what is bad in character and active in its destructive influence. Biblical language identifies it first through the Hebrew term ra', denoting anything opposed to God's intent and producing evil effects, whether in thoughts, words, or deeds. The New Testament employs kakos to describe wickedness in character and poneros to portray evil that actively generates labor, pain, sorrow, and further rebellion, the very quality embodied by the wicked one. Scripture presents this evil nature as already operative from birth because of fleshly existence, selling the individual under sin and creating an ongoing internal war even after conversion. Paul illustrates the struggle decades into his calling, acknowledging that a law of evil remains present in his members despite his renewed mind. Christ reinforces the point by addressing disciples as poneros while contrasting them with the Father's consistent goodness. The heart itself is declared deceitful above all things and desperately wicked, capable of self-deception that masks pride and self-righteousness. This evil nature manifests outwardly in sins that proceed from within, defiling relationships and requiring deliberate resistance rather than external avoidance alone. Recognition of its reality demands the same moral clarity that names enemies without equivocation. The broader message therefore calls believers to arm themselves with the mind of Christ, applying fasting, prayer, study, and meditation to stamp out carnal impulses and return good for evil. Such commitment fulfills the calling to suffer wrongfully while pursuing righteousness, ensuring that the accumulated evil of the past and the residual evil retained after conversion are progressively overthrown.

Human nature is evil, and the Flood did not change it. In Genesis 8:21, after the Flood had destroyed nearly all humanity, God repeats His verdict from Genesis 6:5: the imagination of man's heart is evil from his youth. The Flood executed judgment on sinners and left only eight people with a chance to do better, but it changed nothing about human character. The phrase "from his youth" allows only a narrow window of potential goodness in early childhood. Babies are born morally neutral, able to do good or evil, yet because of the flesh they lean toward selfishness and sin. Carnal nature wants everything for itself. Everyone since the Flood has had the same wicked nature, and humanity has not improved, whatever evolutionists argue. Scripture, the story of God's redemption of mankind, shows both the depth of man's sin and the sublimity of His gracious love. David describes human corruption in Psalm 14, and Jeremiah 17:9 says the heart is deceitful above all things and desperately wicked, even incurably sick. Paul gives a full indictment in Romans 3:9-18. Sin comes in degrees, and not everyone is a flagrant sinner. Many try hard to do good as they understand it. Yet in God's eyes humans grow corrupt from a young age, and a single sin is enough to incur the penalty of death.