Humans consist of both body/flesh and soul/spirit, which is how our physical bodies can perish, but we can still go on to live forever with Christ if we are believers. (Side note: some biblical scholars are dichotomists – believing that soul and spirit are synonymous, and some are trichotomists – believing that we are comprised of body, soul AND spirit.) But what is the difference between the flesh and the spirit and how do they function?

The Flesh

The word flesh “refers to the physical body. It however has a moral, or ethical, meaning as well . . . It includes the body, but it also includes the human spirit and soul as animating the body” (Lewis Sperry Chafer, He That Is Spiritual). The word flesh may seem to us to have negative connotations, as if it is the cause and source of all sin. And indeed, many throughout history have felt that way, including the Gnostics - that the flesh is evil and the spirit is good. But God made us with both and both can be used for Him!

“Do you not know that your bodies are temples of the Holy Spirit, who is in you, whom you have received from God? You are not your own; you were bought at a price. Therefore honor God with your bodies” (1 Corinthians 6:19-20).

We can honor God with our bodies – with our flesh! But the key to that is the Holy Spirit.

The Natural Man

The fleshly or unregenerate person does not have the Holy Spirit. The Bible refers to this person as “the natural man.” The natural man (or woman), according to the Bible, is unable to discern the truths of God, comprehending only “human judgments.” This person lives according to the “old nature” (Romans 6:6, 2 Corinthians 5:17, Ephesians 4:22-24, Colossians 3:9, 10), “sinful nature” (Romans 7:18-25) or “earthly nature” (Colossians 3:5) and lacks the presence and the power of God. Conversely, “the spiritual man” is one who possesses the Spirit of God, or Holy Spirit.

“However, as it is written: ‘What no eye has seen, what no ear has heard, and what no human mind has conceived’ – the things God has prepared for those who love him – these are the things God has revealed to us by his Spirit. The Spirit searches all things, even the deep things of God. For who knows a person's thoughts except their own spirit within them? In the same way no one knows the thoughts of God except the Spirit of God. What we have received is not the spirit of the world, but the Spirit who is from God, so that we may understand what God has freely given us. This is what we speak, not in words taught us by human wisdom but in words taught by the Spirit, explaining spiritual realities with Spirit-taught words. The person without the Spirit does not accept the things that come from the Spirit of God but considers them foolishness, and cannot understand them because they are discerned only through the Spirit. The person with the Spirit makes judgments about all things, but such a person is not subject to merely human judgments” (1 Corinthians 2:9-15).

You may have heard the fable of The Scorpion and The Frog. A scorpion that lived in the woods wanted to leave the forest and explore the world. Leaving its home for the first time, it came upon the banks of a raging river, but the scorpion could not swim. Spotting a frog, the scorpion asked the frog to carry it across on its back. The frog initially said no, fearing that the scorpion might sting, but the scorpion reasoned with the frog saying, “I won’t sting you, because if I do, we’ll both drown!”

This argument seemed sensible to the frog who agreed to transport the scorpion. The frog began swimming with the scorpion on its back, but halfway across the river, the scorpion stung the frog anyway. The dying frog cried out, “You idiot! Why did you do that?! Now we’re both going to drown!” The scorpion replied, “I’m sorry; it’s my nature.”

Photo credit: ©Getty Images/Yori Hirokawa

The Flesh Desires What Is Contrary to the Spirit of God

Like the scorpion, we have a nature, or a natural state. The Bible teaches that we are born with an earthly or sinful nature. Although we possess both body and spirit, unless we receive the Spirit of God and are transformed (or regenerated) through faith in Jesus Christ, we live according to our “old nature.” Our human spirit has no victory over our flesh. Putting it very simply, this means that if our spirit and our flesh duke it out, the flesh will win. The spirit may be willing, but the flesh is weak (Matthew 26:41). Even though by the Holy Spirit’s power, we can honor God with our bodies, our flesh naturally desires what is contrary to the Spirit.

“For the flesh desires what is contrary to the Spirit, and the Spirit what is contrary to the flesh. They are in conflict with each other, so that you are not to do whatever you want” (Galatians 5:17).

The Human Spirit

When the Bible refers to the human spirit, it is referring to “the immaterial part of man, a term used interchangeably with ‘soul’” (Wayne Grudem, Systematic Theology). Our flesh and spirit were created and intended by God to function together in unity and harmony, but sin destroyed this unified function. The answer to the problem of the disharmony and disunity between our flesh and our spirit is the Spirit of God!

The Spiritual Man

It is the Spirit of God that gives spiritual life to our human spirits! In order for this spiritual life to be ours, we must be born again! We were born physically with a physical body into a physical family. We must also be born spiritually, by the Spirit of God, into spiritual life and a spiritual family.

“Flesh gives birth to flesh, but the Spirit gives birth to spirit. You should not be surprised at my saying, 'You must be born again'” (John 3:6-7).

“You, however, are not in the realm of the flesh but are in the realm of the Spirit, if indeed the Spirit of God lives in you. And if anyone does not have the Spirit of Christ, they do not belong to Christ. But if Christ is in you, then even though your body is subject to death because of sin, the Spirit gives life because of righteousness. And if the Spirit of him who raised Jesus from the dead is living in you, he who raised Christ from the dead will also give life to your mortal bodies because of his Spirit who lives in you. Therefore, brothers and sisters, we have an obligation – but it is not to the flesh, to live according to it. For if you live according to the flesh, you will die; but if by the Spirit you put to death the misdeeds of the body, you will live. For those who are led by the Spirit of God are the children of God. The Spirit you received does not make you slaves, so that you live in fear again; rather, the Spirit you received brought about your adoption to sonship. And by him we cry, ‘Abba, Father.’ The Spirit himself testifies with our spirit that we are God's children” (Romans 8:9-16).

Photo credit: ©Getty Images/Aaron Amat

Kristi Walker has been a missionary in Berlin, Germany for over 15 years working with an international church as the Director of Student Ministries. She is the author of two books - Disappointment: A Subtle Path Away from Christ and Convinced. Applying Biblical Principles to Life’s Choices.