The Flesh (Sin-Nature)

We’re continually told to fight against our flesh and its sinful urges. However most of us don’t know just what the flesh is –so we’re hopelessly left to battle our thoughts, regret yesterday’s decisions and dread what tomorrow holds.

The objective here is to clear away the smoke and carnage from the battlefield within –to make life as a believer joyful and the battles winnable. Just for now, set aside those oppressive feelings and consider the following observations.

Our Human Makeup

Genesis chapter two describes our human makeup. It’s where Adam said of his mate, “This is now bone of my bones, And flesh of my flesh; She shall be called Woman, Because she was taken out of Man.” Bone, in Hebrew, refers to the whole living-body –including what it does. Flesh alludes to the body’s motivation –the cause for what it does.

The phrase “bone and flesh” is sprinkled throughout the Old Testament to call attention to a person’s kindred features, character and family relationships. It’s even part of Jesus’ poignant statement to (doubting) Thomas in Luke chapter 24.

Let’s not lose sight of the context for this Genesis passage. Essentially, Adam was the first earthly king –his land was the pristine Garden of Eden –his subjects were all of the living creatures –his purpose was to rule over them –and his sustenance came from harvesting the garden.

His life appeared to be perfect. Yet, it lacked one thing –there was no one in his kingdom who was like-minded, like-bodied and like-hearted for him to share it with (Genesis 2:18). To satisfy that longing, God separated Adam into two parts –both his whole living-body (bone) and his motivation (flesh). The larger portion remained Adam –and the smaller portion became Eve. There’s an implication: Adam could not fulfill his designated purpose without her joined with him as his helpmate.


The New Testament provides a more granular view of our “whole living-body.” It’s comprised of a physical body, a soul and a human spirit. Allow me to define the obvious…

The physical body is the set of components for performing life-functions –including the formation of the senses. The soul consists of the mind (for thinking, planning and decision making), the emotions (for expressing the many aspects of those thoughts) and the will (for carrying out what it wants done). And the human spirit is dedicated to searching out what’s beyond detection by those senses.


The New Testament, like the Old, uses the word “flesh” to convey our natural motivation.

The flesh is neither good nor bad. Rather, God designed it so that we can naturally operate independently –without His constant intervention. However, the flesh’s goal is to remain self-serving and self-sufficient. That’s why it’s also called the sin-nature –there’s no instinctive need for God, for His kingdom or for His life. (Maybe you’re thinking “If it’s sinful, and Romans 8:3 says it is, then why isn’t the flesh bad?” Keep reading…)

Judges of Good and Evil

In Genesis chapter three, Satan said to Eve “…when you eat from it your eyes will be opened, and you will be like God, knowing good and evil.”

Let’s look closer at Satan’s seemingly innocuous words…

Good means “valuable” –it’s what God cherishes and will keep with Him forever. Evil means “worthless” –it’s what He is going to discard into the furnace. And knowing means “to competently discern,” “to fully comprehend,” “to be thoroughly familiar with.” It’s about judging the eternal reward or penalty that a person deserves.

Eve was a small part of the creation, not the Creator. So she didn’t have the capacity to know (to competently discern, to fully comprehend, to be thoroughly familiar with) the purposes of the many parts of His creation. Trying to “be like God, knowing good and evil” is why He put a separation between them and Himself –and He called that separation “death.” But it wasn’t without first providing a way to life.

In His warning, God identified two trees. First He told them about the tree of life –and afterward He told them about the tree of death. Those trees represent the only two laws by which He evaluates everyone. Romans 8:1-2 labels them the law of the Spirit of life which describes the ways of eternal life –and the law of sin and death which describes why we need that life.

I call the second one “the tree of death” because God said “for in the day that you eat from it you will surely die.” There’s no “if you eat from it” –it was just a matter of time until she did. Rebellion (sin) and death are our inheritance from her. (Some maintain that God didn’t directly tell her to not eat the fruit …maybe to excuse her and somehow shift the blame to Adam. But God told them both at the same time –it was while they shared the same body.)

Eating the fruit from that tree wasn’t the tipping point –eating it was simply proof that she wanted to be the ultimate decider of what’s “best.” It was evidence of what was already in her heart.

Eve’s flesh –her natural motivation– was to seize control of her life and whatever affected it. She wasn’t satisfied with merely being her husband’s helpmate. Genesis chapter three is quite telling (in its veiled way). “Your desire will be for your husband, And he will rule over you.” She didn’t like being ruled –she wanted to be king over all. Likewise, we –her heirs– try to be God rather than accepting His sovereignty over us.

Romans chapter five uses the imagery of a king to describe death. We start out in its kingdom, under its reign –and we can’t escape by walking up to the tree of life and picking its fruit. That tree was taken out of human reach and angels stand guard. They carry a blazing sword that serves as a welcoming beacon for those who seek eternal life and as a foreboding deterrent to those who are still trying to be God –the Judge. That tree is pictured by the cross and its fruit is Jesus’ blood and flesh (from John 6:51-58).

Law of the Flesh

Laws describe how things work. As such, the “law of the flesh” describes our natural motivation for daily-life.

Most of our childhood is spent learning what to do when our senses detect a change in the surroundings –or when memories emerge from the past –or when contemplating the future. Over time, the flesh learns what responses to those stimulations yield the “best” results. They become the law that we live by. As new circumstances are encountered we make (supposed) improvements to that law –even adapting bits and pieces from moral and civil codes and possibly part of what’s in the Bible. This law is the basis of what we believe is right and wrong.

Here are a few potential cases (some from a secular setting and some from church) –each listed with its stimulation and a probable response.

When danger looms, we quickly look for help from any source –to regain a sense of security. Seeing detestable conditions of health leads us to change our eating habits and add exercise to our regimen –to become healthier and happier. When criticized, we berate the critic –to maintain our reputation. After routinely seeing beggars on street corners, we pretend they don’t exist –to avoid feeling guilty for not helping…

After hearing a condemning sermon, we try to change our behaviors (through anger-management, addiction-control, financial-planning) –to appear godly. When in public, we present ourselves as kind, gentle and caring (more so than normal) –to appear spiritual. We stay on our knees in hopeful prayer for hours, we financially and personally help with the needs of the church, and we witness to everyone –to please God…

Your flesh has a law for daily-life similar to this and so does mine.

The heart is the name given to the intangible place within where laws are kept. (It’s sometimes referred to as our “core principles” or “central being” –it’s not referring to our fickle emotions.) Romans 2:14-16 states that our conscience is familiar with our laws (with what we believe is right and wrong) …and our thoughts alternately condemn, defend, accuse and excuse us accordingly.

As Eve’s heirs, it’s natural to attempt fulfilling God’s role of Judge. Our flesh been fooled into thinking that its law (its ability to judge) is perfect. So when it’s confronted with another law that is elevated above its own (the Ten Commandments or practices for godly living or doing the right thing) our flesh rebels against it –and more importantly, against the authority that made it.

The sting of death is sin, and the power of sin is the law; (1 Corinthians 15:56)

But sin, taking opportunity through the commandment, produced in me coveting of every kind; for apart from the Law sin is dead. I was once alive apart from the Law; but when the commandment came, sin became alive and I died; and this commandment, which was to result in life, proved to result in death for me. (Romans 7:8-10)

What is it that enables and gives power to our rebellious ways? Isn’t it “someone” else’s law –a law that’s elevated above our own? Our flesh wholeheartedly believes that it is God –the absolute authority of what’s good and what’s evil– so of course it’s going to rebel.

Our law is what we use to judge –and it’s not just evaluating how pleasant or harsh the circumstances are. We use it to judge the value of people. We even judge ourselves and decide our worth to God.

Failures of the Flesh

Most of the time we operate independently –relying on our strength, endurance, intelligence, knowledge, wisdom, wealth, ability, charisma… That’s how we go through each day –just like the one before– delusionally thinking that we’re being moral, doing the right thing, faithfully following the Ten Commandments, tithing, being in church… We’re not even conscious of the fact that these attempts to do good are what our flesh routinely does to gain adoration.

Jesus said to him, “I am the way, and the truth, and the life; no one comes to the Father but through Me.” (John 14:6)

It is the Spirit who gives life; the flesh profits nothing; the words that I have spoken to you are spirit and are life. (John 6:63)

We might naturally live out our days contently with just our flesh in control –being our own god and working according to our law. But God doesn’t leave us that way. He intentionally frustrates us. Romans 8:19-21 (through the end of that chapter) explains that He has subjected the whole creation to futility to bring about our salvation. For example, He created well-being and disaster (from Isaiah 45:7) –the calm and the storm (from Psalm 148) –good health and sickness (Job 33) –sight and blindness (from John 9). He created all things and nothing exists that He didn’t make (from John 1:1-5).

Our flesh relishes credit for trying to make this world better –eliminating poverty, disease and hunger –and making people moral, law-abiding and kind. But He broke the creation so that these very needs will frustrate us and we will turn to Him for help. It’s not ours to somehow fix what He has put in place to draw people to Himself.

It’s when our world falls apart, when we realize that we can’t really make things turn out the way we want, when emotional peace can’t be found, when our own resources are exhausted– then we might seek God to fix what we can’t. That’s the Holy Spirit interrupting our routines to point out our flesh’s limitations –and each time He does it a little more conspicuously.

Everyday the Holy Spirit confronts us with opportunities to either trust our flesh or to trust Him. In hindsight we can look back at the times that we relied on our flesh and see that He has even worked out those “bad choices” for our good. Gradually, He demonstrates that He is the only One who is trustworthy. That’s how He builds the perfect bond with us –proving His compassion with peace that surpasses comprehension.

What Changed?

When we accepted God’s gift of eternal life, the Holy Spirit formed an inseparable bond with us. We were born-again –born of the Spirit.

Something more took place at that new birth. Although the term brings up unpleasant imagery, it’s essential to take in the New Covenant’s concept of circumcision –circumcision of the heart.

Earlier I noted that the New Testament adds granularity to the term “whole living-body” –stating that it’s comprised of a physical body, a soul and a human spirit. Those pieces are specifically called out with regard to salvation. For a believer, these latter two are destined to live eternally with God. However, the physical body and our fleshly motivations will not –they can not.

This body with its flesh was condemned and it cannot inherit eternal, spiritual life in God’s kingdom (from 1 Corinthians 15:50-58 and the first part of Romans chapter three). However, it has become a vehicle –a vessel– for God to use as His ambassador while we’re here on earth. And He steadily changes the way we think –He “renews” our minds so that we understand and know Him better all the time (from the first part of Romans chapter 12 and 1 Corinthians chapter two).

Moses described this circumcision in Deuteronomy chapters 29 and 30. There he laid out Israel’s then-future failures of following the Law –the failures of their flesh. Just before saying “Today I set before you life and death, choose life” he told them how that life would be possible –God would circumcise their hearts.

Later, Ezekiel was talking about this transformation in regard to Israel (in his chapter 36). God was going to wash them clean and change what motivated their conduct and their actions. He was going to take away their heart of stone –it was dead –separated from Him. In its place He would put a heart of flesh –one that would lead them to a dependence on Him. And He was going to give them a new spirit –new life with the Holy Spirit living within them. (That’s the crux of Hebrews chapter six.)

In Romans, Paul continued the explanation by differentiating between Jews by heritage –and true Jews. “But he is a Jew who is one inwardly; and circumcision is that which is of the heart, by the Spirit, not by the letter; and his praise is not from men, but from God” (Romans 2:29). He amplified his insight in Colossians chapter two…

See to it that no one takes you captive through philosophy and empty deception, according to the tradition of men, according to the elementary principles of the world, rather than according to Christ. For in Him all the fullness of Deity dwells in bodily form, and in Him you have been made complete, and He is the head over all rule and authority;

and in Him you were also circumcised with a circumcision made without hands, in the removal of the body of the flesh by the circumcision of Christ; having been buried with Him in baptism, in which you were also raised up with Him through faith in the working of God, who raised Him from the dead.

When you were dead in your transgressions and the uncircumcision of your flesh, He made you alive together with Him, having forgiven us all our transgressions, having canceled out the certificate of debt consisting of decrees against us, which was hostile to us; and He has taken it out of the way, having nailed it to the cross. (Colossians 2:8-14)

This is another view of Paul’s survey in Romans chapter three where he talked about two journeys –two walks of faith. One is faith in the flesh –apart from God –trusting that we can accomplish whatever we need. The other is faith in Him and everything that He has accomplished through Jesus’ life, death and resurrection –including the reconciliation (total forgiveness) of every repulsive deed of the flesh.

In Galatians chapter five, Paul argued that the Jewish religious practice of physical circumcision was a continuation of depending on their Law to keep themselves on good terms with God. Only two chapters earlier he told them that the Law was like a tutor (a set of pictures or dramas) to lead them to Christ so that they would then live by faith and leave that old way behind (Galatians 3:23-24).

In that chapter he called them “foolish” for allowing themselves to be enslaved again after having started to live by faith (Galatians 3:3). To prove the point he explained that following any part of the Law without keeping it all was useless. At least if they tried to do absolutely everything that was written –and do it perfectly– then they would realize (like he did) that they were dead in their failures.

Our flesh does continue with us until the day we leave this earthly body. But as born-again, spiritual beings we’re no longer controlled by it –we’re not anchored to it. We have another source for our minds to listen to –the Holy Spirit (through our spirit). We certainly aren’t held accountable to the Law of Moses since it (in concert with our flesh) led us to Jesus. We’ve been freed from that barren existence.

There are two lists in that Galatians chapter three –and in many other books of the Bible. One characterizes the results of what the flesh naturally does (it’s the fruit from the tree of death). The other is the results of letting the Holy Spirit do the leading (it’s the fruit from the tree of life –the fruit of the Spirit). Jesus is the One who fulfilled the Law –it’s His biography. He became the single acceptable sacrifice for us. Now we can let Him –who is alive in our bodies– love others (Galatians 2:19-20).

“Crucify the flesh,” “die daily,” “pick up your cross.” –These are pleadings to trust that God has circumcised your heart. Your eternal spiritual being has been freed from your untrusting, naturally independent flesh. And remember that trying to obediently do good gives power back to the rebellious flesh.