There is no such thing as a “sin nature.” The Bible never refers to the “sin nature.” It is a myth of modern theology. However, the Bible DOES teach a lot about the “flesh.” This study looks at Romans 6:19 (and other passages from Romans) to learn what the flesh actually is, and what we are to live in the Spirit rather than in the flesh.
Note that this study is an excerpt from my Gospel Dictionary online course. This course considers 52 key words of the Gospel and thousands of biblical texts. The course contains over 100 hours Bible teaching. You can take the course by joining my online discipleship group.
So let us see what we can learn about the flesh from Romans 6:19 and other texts.

The Flesh in Romans 6:19
I speak in human terms because of the weakness of your flesh โฆ
For when we were in the flesh, the sinful passions which were aroused by the law were at work in our members to bear fruit to death.
โฆ So then, with the mind I myself serve the law of God, but with the flesh the law of sin.
For to be carnally minded is death, but to be spiritually minded is life and peace.ย Because the carnal mind is enmity against God; for it is not subject to the law of God, nor indeed can be.
The concept of flesh is prominent in the Pauline epistles. In general, when Paul refers to the flesh, he is referring to โthe whole of manโs physical existenceโ (TDNT, VII:125). This not only includes the tissue that makes up the body, but also a personโs mental capacities, inner anxieties, and physical strength. For Paul, the term flesh โdescribes earthly life in its totalityโ (TDNT, VII:126).
As a result of this way of thinking, Paul frequently differentiates between the earthly life of the flesh and the heavenly life of the Spirit. The earthly life is not inherently evil or hostile to God; it is simply limited in its scope and understanding. The early life of the flesh lacks all of the information needed to make proper decisions about what is important in life and how to understand the events of life.

So, for example, when Paul writes in Romans 6:19ย about speaking in human terms because of the weakness of the flesh, he is simply saying that he is describing how life works from physical, earthly, and human perspective. When humans sin, we do not think we are giving up our freedom to the sin. To the contrary, sin often seems quite liberating. But Paul point out that this is only because of the weakness of our flesh (or mind, in this case), to understand what is really happening.
We only gain proper perspective about slavery to sin and freedom in the Spirit through the regeneration that comes as a result of the indwelling Holy Spirit (Romans 6:1-14). The spiritual awakening and understanding that comes through Spirit baptism helps us see the world, ourselves, and our slavery to sin in a whole new light. Prior to this awakening, the flesh is unable to fully comprehend or grasp the danger of giving ourselves over to sin. But the way of slavery to sin is the way that leads to death (Romans 6:21-23).
This concept of ignorant flesh leading to sin and death is further explained in Romans 7.
The Flesh in Romans 7:5, 25
In Romans 7, Paul also shows how the law works together with the flesh to bring about sin and death. The flesh, being ignorant of the ways of the Spirit, loves to focus on externals as a way to determine what is right and wrong. The law is only concerned with external actions and behaviors. One can keep the whole law, and yet still not have the true, inner change of heart that is wanted and desired by God. This is why God did not want or desire to give the law to the people of Israel. He wanted a relationship based on love, rather than a religion based on law.
But when the law is followed in the blindness of the flesh, it leads a person to think that they are doing what God wants, and are therefore, โin the rightโ with God. It further allows people to judge, accuse, and condemn other people for not obeying the law. Such condemnation and accusation leads them into a life of death. They themselves do not accomplish what God actually wants in life, but instead die to His purposes and plans for them.
Furthermore, as a result of their judgment of law-breakers, they feel justified in their zeal to call for the condemnation and killing of people whom they view as the enemies of God. The law and flesh work together to create a religion based on death. The โsinful passionsโ that Paul speaks of in Romans 7:5, therefore, are not primarily the passions of lust and sensuality, but the zealous passions of religion which lead people to kill and condemn in Godโs name.
In Romans 7:25, Paul contrasts the law of God with the law of sin. His mind, that is, his spiritual mind, serves the law of God, but his flesh serves the law of sin. Paul has already pointed out that the law of sin is the religious Mosaic Law that is based on externals. This means that the law of God cannot be the same as the religious law. Rather, the law of God is a spiritual law written upon the heart of the regenerate person. It is not based on a list of things to do, but on a relationship of love for God and others.

The Flesh in Romans 8:6-7
As a result of living according to the law of God, all condemnation and accusation is done away with. We are not condemned; nor do we condemn (Romans 8:1-8). It is only the fleshly, carnal mind that is still focused on the externals of the religious law of sin that condemns and accuses others. This way of life, as Paul already stated, leads only to death for all involved.
But true life and liberty is found by allowing the Spirit to work with our mind and show us what God really wants for us in life (Romans 8:6-7). We live our best life when we do not allow our fleshly mind with its limited perspective to rule and dominate, but instead allow the illuminating Spirit to guide our thoughts and actions so that we love, accept, and forgive others, just as God loves, accepts, and forgives us (Romans 8:16-17, 26-39).
The carnal mind therefore, is not evil. It is not the โsin nature.โ It is simply ignorant. It does not have all the information about God and His true will for lives. The carnally minded person sees only externals, and bases its life and actions toward others on the external commands of religious law.
But this way of living results only in death. It is death for the person because they are not โaliveโ as God intended or desired, and it is death for others because living according to the law of sin leads a person to condemn and kill others in the name of God. They think this is what God wants, but it is actually the opposite.
The spiritually minded person sees the whole truth, and knows that living like God means loving like God.
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But sending a runner was not always the best option. Runners could not be used when the distance was too far, when the message was too urgent, or when enemy forces were in the way. So the Roman military devised an ingenious solution for such situations. They developed a system of communication which could quickly send short messages over long distances and even to other units that were separated from the main force.








This bring up the third reason some prayers require perseverance. Sometimes, God does not immediately answer our requests because He wants us to remain in communication with Him. God is not playing games with us by making us wait for some of the things we request, but at the same time, God doesnโt want us to play games with Him.
Victor Walter also found that most prayers were for groups of people, rather than for individuals. If a prophet or apostle had an issue with a person or a solution for a problem they faced, they spoke directly to that person about it, rather than praying to God for it.
Indeed, Paul has firsthand knowledge and experience of this front line warfare, and he indicates this by describing himself as an ambassador in chains. Paul wrote the letter of Ephesians from prison, likely while being chained between two Roman guards. And he was in prison because he had declared the gospel, and was facing a death sentence for the same reason.

As we go about our own work as Christians, we too must keep a sword strapped to our side. Not a sword made from steel with which to kill other peopleโfor our struggle is not against flesh and bloodโbut a spiritual sword with which to demolish spiritual enemies and defend ourselves against all the wiles of the devil.
Everybody knows what a sword looks like. And we have likely all seen pictures or movies of Roman soldiers carrying their sword. The swords that were typically used in Paulโs day were made of iron, and were double-edged. Like many swords, they came to a point, had a hilt, and a guard to protect the hand of the sword bearer. The Roman sword also had a metal knob at the base of the hilt which could be used to bash an enemy in the face or head if needed.
We would think that of all the pieces of spiritual armor, the sword would be the one piece with which the soldier could attack the enemy, but this is not really the case. Even here, as with all the other pieces of armor, the short sword was primarily used for defense. It was not used to advance against an enemy army, but was used to defend a position on the field of battle which had already been gained.
The graphฤ, the writings, or the logos, the Word of God, refers to what we call the Bible, as a written revelation from God. It is important to note that the second term, logos, can also refer to Jesus as the living, incarnate Word of God (cf. John 1:1-11). There is a written logos, the Bible, and a living Logos, Jesus, and both are divine revelations from God.
We must exercise with the Bible until it is stamped into our minds, so that when it is needed, our muscle memory kicks in and the use of the sword becomes second nature and automatic.
We could sit in a circle and say, โVery often, we feel like God does not love us and cannot forgive us for some sin we have committed. What truths or verses in Scripture can remind us of Godโs infinite love and complete forgiveness?โ (Some possible answers: John 3:16; Rom 5:8; 8:38-39; 1 John 2:1-2; 4:7-10).
And you must keep immersing yourself in Scripture, day in and day out, so that you know what the Scripture says and how to apply its promises to your life when lies and deceptions of the devil start to tear you down. If you want to have your sword with you in spiritual battle, you need to be skilled with the Word of God. And the only way to gain skill in Scripture is to practice using Scripture as much as possible.
Therefore, if we want to change our actions, we must begin by changing our thoughts. To change how we act, we must begin by changing how we think.
The helmet in Paulโs day was most often made of heavy bronze or iron, and had additional pieces of metal which came down to protect the side of the face. The soldiers would often pack their helmets with some sort of cloth or padding to make them more comfortable on the head.
But what purpose did the helmet serve?
Specifically, in Ephesians 2, Paul describes the exact form of deception he wants his readers to be liberated from. In
And since our thoughts come from the brain, this is why Paul equates salvation with the helmet. The helmet protects our head.
It begins with how we think about other people. The helmet protects our brain, and the thoughts of our brain guide our emotions, which in turn determine our actions. So if we want to treat people like Jesus treated them, we must learn to think about people the way He thought about them.
We must tell people that they are forgiven and accepted, not just by God, but by us as well. We must speaks words of beauty and praise to other people for the good things they do and the accomplishments they attain.

Remember, the strength and genius of the Roman military was their ability to stand firm and stay in once place on the field of battle, defending their small piece of land from any and all attackers. The shield served a significant role in this strategy.



Faith, as taught in the Bible, can be defined as a reasonable certainty about any truth claim or statement of fact.
When temptations do get through, and when we get wounded by the fiery darts of the devil, it is because we have dropped our shield. The only way the fiery darts of temptation get past the protective shield of God is when we have not properly taken up the shield of faith, as Paul instructions in Ephesians 6:16. When the shield drops, when we let down our guard, it is then that the fiery darts are able to get through and wound us.
So to grow our faith, to walk by faith, to live by faith, and to take up the shield of faith, we must begin with the facts and truths we know to be true, and then build upon these ideas with more truths and ideas from Scripture.
Do you see? As we come to learn and believe these promises of God, they become a shield and a barrier protecting us from all the lies of the devil.