The key is found in (2 Corinthians 10:3: though we walk in the flesh, we do not war after the flesh: our walk – no man can avoid; the war – every man must avoid.
Flesh as literally the human body:
- But you know that it was because of a bodily illness that I preached the gospel to you the first time; (Galatians 4:13)
- And because of the surpassing greatness of the revelations, for this reason, to keep me from exalting myself, there was given me a thorn in the flesh, a messenger of Satan to buffet me–to keep me from exalting myself! (2 Corinthians 12:7)
- For even though I am absent in body, nevertheless I am with you in spirit, rejoicing to see your good discipline and the stability of your faith in Christ. (Colossians 2:5)
- For I want you to know how great a struggle I have on your behalf, and for those who are at Laodicea, and for all those who have not personally seen my face, (Colossians 2:1)
- But if [I am] to live [on] in the flesh, this [will mean] fruitful labor for me; and I do not know which to choose. (Philippians 1:22)
- Yet to remain on in the flesh is more necessary for your sake. (Philippians 1:24)
- Yet He has now reconciled you in His fleshly body through death, in order to present you before Him holy and blameless and beyond reproach– (Colossians 1:22)
- Yes, they were pleased [to do so,] and they are indebted to them. For if the Gentiles have shared in their spiritual things, they are indebted to minister to them also in material things. (Romans 15:27)
- But I buffet my body and make it my slave, lest possibly, after I have preached to others, I myself should be disqualified. (1 Corinthians 9:27)
Sins of the flesh are more than sexual sins: trouble in the flesh. “But if you should marry, you have not sinned; and if a virgin should marry, she has not sinned. Yet such will have trouble in this life, and I am trying to spare you.” (1 Corinthians 7:28)
The flesh meaning “humanly speaking:”
- Concerning His Son, who was born of a descendant of David according to the flesh, (Romans 1:3)
- Because by the works of the Law no flesh will be justified in His sight; for through the Law [comes] the knowledge of sin. (Romans 3:20)
- What then shall we say that Abraham, our forefather according to the flesh, has found? (Romans 4:1)
- Let no one deceive you with empty words, for because of these things the wrath of God comes upon the sons of disobedience. (Ephesians 5:6)
The flesh meaning other people or human purposes:
- To reveal His Son in me, that I might preach Him among the Gentiles, I did not immediately consult with flesh and blood, (Galatians 1:16)
- Therefore, I was not vacillating when I intended to do this, was I? Or that which I purpose, do I purpose according to the flesh, that with me there should be yes, yes and no, no [at the same time]? (2 Corinthians 1:17)
- For we are the [true] circumcision, who worship in the Spirit of God and glory in Christ Jesus and put no confidence in the flesh, although I myself might have confidence even in the flesh. If anyone else has a mind to put confidence in the flesh, I far more.(Philippians 3:3-4)
- Since many boast according to the flesh, I will boast also. (2 Corinthians 11:18)
The flesh as pre-Christian: “For while we were in the flesh, the sinful passions, which were [aroused] by the Law, were at work in the members of our body to bear fruit for death.” (Romans 7:5)
The flesh as sub-Christian: “For you are still fleshly. For since there is jealousy and strife among you, are you not fleshly, and are you not walking like mere men?” (1 Corinthians 3:3)
The flesh that is totally Pauline: connected with sin, ethics
- For we know that the Law is spiritual; but I am of flesh, sold into bondage to sin. (Romans 7:14)
- But I see a different law in the members of my body, waging war against the law of my mind, and making me a prisoner of the law of sin which is in my members. Wretched man that I am! Who will set me free from the body of this death? Thanks be to God through Jesus Christ our Lord! So then, on the one hand I myself with my mind am serving the law of God, but on the other, with my flesh the law of sin. (Romans 7:23-25)
- For the mind set on the flesh is death, but the mind set on the Spirit is life and peace, (Romans 8:6)
- Because the mind set on the flesh is hostile toward God; for it does not subject itself to the law of God, for it is not even able [to do so]; (Romans 8:7)
- So then, brethren, we are under obligation, not to the flesh, to live according to the flesh– for if you are living according to the flesh, you must die; but if by the Spirit you are putting to death the deeds of the body, you will live. (Romans 8:12-13)
- But put on the Lord Jesus Christ, and make no provision for the flesh in regard to [its] lusts. (Romans 13:14)
- For you were called to freedom, brethren; only [do] not [turn] your freedom into an opportunity for the flesh, but through love serve one another. (Galatians 5:13)
- For the flesh sets its desire against the Spirit, and the Spirit against the flesh; for these are in opposition to one another, so that you may not do the things that you please. (Galatians 5:17)
- Therefore, having these promises, beloved, let us cleanse ourselves from all defilement of flesh and spirit, perfecting holiness in the fear of God. (2 Corinthians 7:1)
- Among them we too all formerly lived in the lusts of our flesh, indulging the desires of the flesh and of the mind, and were by nature children of wrath, even as the rest. (Ephesians 2:3)
The flesh is not referring to only the grosser sins: “Now the deeds of the flesh are evident, which are: immorality, impurity, sensuality, 20 idolatry, sorcery, enmities, strife, jealousy, outbursts of anger, disputes, dissensions, factions” (Galatians 5:19-20)
The flesh as the old man:
- That, in reference to your former manner of life, you lay aside the old self, which is being corrupted in accordance with the lusts of deceit, (Ephesians 4:22)
- Knowing this, that our old self was crucified with [Him,] that our body of sin might be done away with, that we should no longer be slaves to sin; (Romans 6:6)
- Now those who belong to Christ Jesus have crucified the flesh with its passions and desires. (Galatians 5:24)
The flesh in Greek thought: the prison of the soul, basically evil, but Paul had a high view of the body.
- Therefore God gave them over in the lusts of their hearts to impurity, that their bodies might be dishonored among them. (Romans 1:24)
- Flee immorality. Every [other] sin that a man commits is outside the body, but the immoral man sins against his own body. (1 Corinthians 6:18)
- I urge you therefore, brethren, by the mercies of God, to present your bodies a living and holy sacrifice, acceptable to God, [which is] your spiritual service of worship. (Romans 12:1)
- Do you not know that you are a temple of God, and [that] the Spirit of God dwells in you? (1 Corinthians 3:16)
- Or do you not know that your body is a temple of the Holy Spirit who is in you, whom you have from God, and that you are not your own? (1 Corinthians 6:19)
- Or what agreement has the temple of God with idols? For we are the temple of the living God; just as God said, “I WILL DWELL IN THEM AND WALK AMONG THEM; AND I WILL BE THEIR GOD, AND THEY SHALL BE MY PEOPLE. (2 Corinthians 6:16)
- The resurrection of the body is dealt with in (1 Corinthians 15:1-58)
- But if the Spirit of Him who raised Jesus from the dead dwells in you, He who raised Christ Jesus from the dead will also give life to your mortal bodies through His Spirit who indwells you. (Romans 8:11)
- And not only this, but also we ourselves, having the first fruits of the Spirit, even we ourselves groan within ourselves, waiting eagerly for [our] adoption as sons, the redemption of our body. (Romans 8:23)
- Who will transform the body of our humble state into conformity with the body of His glory, by the exertion of the power that He has even to subject all things to Himself. (Philippians 3:21)
Paul uses the word aphorme: the point which an attack can be launched with the greatest possibility of success.
- For you were called to freedom, brethren; only [do] not [turn] your freedom into an opportunity for the flesh, but through love serve one another. (Galatians 5:13)
- The flesh is weak and will fall to these attacks. Paul often refers to the universal human experience, the idea of helplessness, fallibility and sinfulness of human nature without Christ. The flesh is man apart from God.
This material is from William Barclay, the Mind of St. Paul, 1975.