Wednesday, February 11, 2026
Tonight’s Study, Session 6: Core Belief #5 – Humanity and Sin
Introduction: The human condition is defined as inherently sinful due to the fall of Adam, characterized by a natural rebellion against God (sin nature) and a separation from Him. Sin is defined as missing God’s mark, transgressing His law, and rebellion. Through faith in Jesus Christ, humanity can receive forgiveness, restoration, and freedom from the eternal penalty of sin.
Humans are created in God’s image but born with a “sin nature” – a natural inclination to choose self over God. The human condition is spiritually blind, morally ruined, and enslaved by sin.
The sin nature is that aspect in humanity that makes us rebellious against God. When we speak of the sin nature, we refer to the fact that we have a natural inclination to sin; given the choice to do God’s will or our own, we will naturally choose to do our own thing. Therefore, we are not sinners because we sin, we sin because we are sinners.
Proof of the sin nature abounds. No one has to teach a child to lie or be selfish; rather, we go to great lengths to teach children to tell the truth and put others first. Sinful behavior comes naturally. The news is filled with tragic examples of mankind acting badly. Wherever people are, there is trouble. C.H. Spurgeon said, “As the salt flavors every drop in the Atlantic, so does sin affect every atom of our nature. It is so sadly there, that if you cannot detect it, you are deceived.”
The Bible explains the reason for the trouble. Humanity is sinful, not just in theory or in practice but by nature. Sin is part of the very fiber of our being. The Bible speaks of “sinful flesh” in Romans 8:3. It’s our “earthly nature” that produces the list of sins in Colossians 3:5. And Romans 6:6 speaks of “the body ruled by sin.” The flesh-and-blood existence we lead on this earth is shaped by our sinful, corrupt nature.
Romans 8:3 – For what the law could not do in that it was weak through the flesh, God did by sending His own Son in the likeness of sinful flesh, on account of sin: He condemned sin in the flesh,
Colossians 3:5 – Therefore put to death your members which are on the earth: fornication, uncleanness, passion, evil desire, and covetousness, which is idolatry.
Romans 6:6 – knowing this, that our old man was crucified with Him, that the body of sin might be done away with, that we should no longer be slaves of sin.
The sin nature is universal in humanity. All of us have a sinful nature, and it affects every part of us. This is the doctrine of total depravity, and it is Biblical.
Biblical Proof Texts to Support the Doctrine of Total Depravity
Isaiah 53:6 – All we like sheep have gone astray; We have turned, every one, to his own way; And the Lord has laid on Him the iniquity of us all.
Romans 3:10 – As it is written: “There is none righteous, no, not one;
Romans 3:23 – for all have sinned and fall short of the glory of God,
Romans 7:14 – For we know that the law is spiritual, but I am carnal, sold under sin.
Romans 7:24-25 – O wretched man that I am! Who will deliver me from this body of death? I thank God—through Jesus Christ our Lord! So then, with the mind I myself serve the law of God, but with the flesh the law of sin.
Ecclesiastes 7:20 – For there is not a just man on earth who does good And does not sin.
1 John 1:8 – If we say that we have no sin, we deceive ourselves, and the truth is not in us.
No One Is Exempt!
Even children have a sin nature. We have all been conceived in sin.
Psalm 51:5 – Behold, I was brought forth in iniquity, And in sin my mother conceived me.
Psalm 58:3 – The wicked are estranged from the womb; They go astray as soon as they are born, speaking lies.
Where did the sin nature come from? Scripture says that God originally created humans good and without a sin nature (Genesis 1:27). However, Genesis 3 records the disobedience of Adam and Eve. By that one action, sin entered into their nature. They were immediately stricken with a sense of shame and unfitness, and they hid from God’s presence (Genesis 3:8). When they had children, Adam’s image and likeness was passed along to his offspring (Genesis 5:3). The sin nature manifested itself early in the genealogy: the very first child born to Adam and Eve, Cain became the very first murderer (Genesis 4:8).
Genesis 1:27 – So God created man in His own image; in the image of God He created him; male and female He created them.
Genesis 3:8 – And they heard the sound of the Lord God walking in the garden in the cool of the day, and Adam and his wife hid themselves from the presence of the Lord God among the trees of the garden.
Genesis 5:3 – And Adam lived one hundred and thirty years, and begot a son in his own likeness, after his image, and named him Seth.
Genesis 4:8 – Now 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 killed him.
From generation to generation, the sin nature was passed down to all of humanity: “Sin entered the world through one man, and death through sin, and in this way death came to all people, because all sinned” (Romans 5:12). The sin nature of mankind leads to death (Romans 6:23).
Romans 6:23 – For the wages of sin is death, but the gift of God is eternal life in Christ Jesus our Lord.
Other consequences of the sin nature are hostility toward God and ignorance of His truth (Romans 8:7-8; 1 Corinthians 2:14).
Romans 8:7-8 – Because the carnal mind is enmity against God; for it is not subject to the law of God, nor indeed can be. So then, those who are in the flesh cannot please God.
1 Corinthians 2:14 – But the natural man does not receive the things of the Spirit of God, for they are foolishness to him; nor can he know them, because they are spiritually discerned.
There is only one Person in the history of the world who did not have a sin nature: Jesus Christ. His virgin birth allowed Him to enter our world while bypassing the curse passed down from Adam. This allowed Jesus to be sacrificed on the cross as our perfect substitute, “a lamb without blemish or defect” (1 Peter 1:19). Reformer John Calvin puts it in perspective: “For certainly, Christ is much more powerful to save than Adam was to ruin.”
1 Peter 1:19 – but with the precious blood of Christ, as of a lamb without blemish and without spot.
It is through Christ that we are born again. “That which is born of the flesh is flesh, and that which is born of the Spirit is spirit” (John 3:6). When we are born of Adam, we inherit his sin nature; but when we are born again in Christ, we inherit a new nature: “Therefore, if anyone is in Christ, the new creation has come: the old has gone, the new is here!” (2 Corinthians 5:17).
We don’t lose our sin nature once we receive Christ. The Bible says that sin remains in us and that a struggle with that old nature will continue as long as we are in this world. Paul bemoaned his own personal struggle (Romans 7:15-25). But we have help in the battle – divine help. The Sprit of God takes up residence in each believer and supplies the power we need to overcome the pull of the sin nature within us (1 John 3:9).
1 John 3:9 – Whoever has been born of God does not sin, for His seed remains in him; and he cannot sin, because he has been born of God.
Are you a lover of God struggling with sin, or a lover of sin struggling with God?
Conclusion: If we were left to our own humanity, with its sin nature and inclination toward sin, we would all be doomed and destined to hell. But through a personal relationship with Christ, that has all changed. There is hope and help to all who repent and put their faith in trust in Christ as Lord and Savior. As 2 Corinthians 5:21 says, “For He made Him who knew no sin to be sin for us, that we might become the righteousness of God in Him.” Since Jesus took all of our sin to the cross and died in our place and was raised from the dead, sin no longer has dominion over us, and we no longer have to fear the spiritual death it brings. Jesus gives us this eternal promise in John 11:25, “I am the resurrection and the life. He who believes in Me, though he may die, he shall live.”
Next Week, Session 7: Core Belief #6 – Salvation