As an introductory thought before expositing this "ugly list", it is noteworthy that as I have read many sermons and commentaries on walking in the Spirit and not the flesh, I have observed that there is a definitive tendency to only briefly exposit these vile vices. It is not that the authors and pastors don't recognize the seriousness of these sins, but that they nevertheless seem to "shy away" from discussing them in any depth. This list is not "fun" to write commentary on, and is in some ways very "painful", as it is like picking up a mirror and looking at my own face. It seems to me that although we certainly should not "major" on these negatives, neither should we gloss them over as "dirty sins" (which they are), but that we should do what God calls us to do with all of Scripture...we should meditate on these painful passages...we should seek to grasp their heinousness...we should seek to recognize how offensive they are to God's holiness, etc, etc. Then, having our senses trained, we might be forearmed the next time our unredeemed flesh seeks to cause us to act out or lash out with one of these sins. Thus armed with God's truth, we can instead choose the will of God, and praise Him for His enabling grace to walk in the power of His Spirit, Who gives us the victory in Christ Jesus our Lord. Amen.

James Montgomery Boice introduces the two sets of lists explaining that...

the lists are more than a mere proof of what he has written earlier. For by raising these particulars of conduct, Paul also provides a checklist for measuring the conduct of those who consider themselves spiritual. If one's conduct is characterized by the traits in the first list, then he is either not a believer or else a believer who is not being led by God's Spirit. The same standards of evaluation hold true for churches. (Gaebelein, F, Editor: Expositor's Bible Commentary 6-Volume New Testament. Zondervan Publishing)

How to you know if you are walking in the Spirit? Too often we talk as if this is some mystical experience available only to a select few who know the secret of the victorious Christian life. Paul does away with the "mystery" and says it will be evident - clearly if the flesh is continuously hostile to the Spirit, it follows that when the deeds of the flesh are evident in our lives we are not walking by the Spirit, allowing ourselves to be led by the Spirit or keeping in step with the Spirit. Paul's point in this very practical section is that the works of the flesh are plainly visible so that fleshly behavior (often referred to as carnal behavior) is readily apparent to all observers. In other words, to use a Biblical analogy, "the tree is known by its fruit", in this case "bad fruit" or more accurately the deeds or works.

The Greek literally reads evident now are... which clearly emphasizes the visibility of these deeds. There are in plain view and obvious to one and all. While the flesh nature per se may not be visible, its deeds are clearly erupt forth in public works and words! Paul now proceeds to list some (but far from all) of the deeds that emanate from the desire of the flesh (note Galatians 5:16), which the KJV terms the lust of the flesh. When we hear "lust" we immediately think "sexual", but clearly that is not the sole manifestation of the depraved flesh as indicated by this "vice list" of 15 sins, which have been categorized roughly into 4 categories - sexual (sensual sins), religious (idolatry and sorcery), social (interpersonal relations) and drink.

Lightfoot comments that...

Though no systematic classification is to be looked for in the catalogue which follows, yet a partial and unconscious arrangement may perhaps be discerned. The sins here mentioned seem to fall into four classes: (1) Sensual passions, ‘fornication, uncleanness, licentiousness’; (2) Unlawful dealings in things spiritual, ‘idolatry, witchcraft’; (3) Violations of brotherly love, ‘enmities...murders’; (4) Intemperate excesses, ‘drunkenness, revellings.’ From early habit and constant association a Gentile Church would be peculiarly exposed to sins of the first two classes. The third would be a probable consequence of their religious dissensions, inflaming the excitable temperament of a Celtic people. The fourth seems to be thrown in to give a sort of completeness to the list, though not unfitly addressed to a nation whose Gallic descent perhaps disposed them too easily to these excesses (Epistle of St Paul to the Galatians)

C Norman Bartlett explains that...

Having reminded his readers that a relentless warfare between the old nature and the new nature is inescapable, the apostle in the remainder of Galatians 5 draws a picture of the sharp and vivid contrast between the works of the flesh and the fruits of the Spirit. We turn to his comprehensive catalogue of the sins of the flesh in Galatians 5:19-21. It may be well to remind ourselves again at this point that the word "flesh" here indicates not the body - although that is included - but the natural man, the old nature.

"Now the works of the flesh are manifest . . ." Let us pause right here. "The works of the flesh are manifest" - that is to say, they are going to be shown for what they really are, in all their naked hideousness. The Word strips of glamour the sins that the world clothes with glamour. We do well from time to time to gaze upon the loathsome picture of sin which Scripture paints. But the average man pays more heed to the world's light estimate of sin than to what GOD says about it, blissfully unmindful of the fact that the sins which men call smart will smart throughout all eternity unless they are washed away in the penitently accepted blood of Jesus. Our souls are the more easily tarnished by the sins that are varnished (Ed note: covered or concealed in such a way as to making it superficially attractive). The fashion of sin is not changed by making it fashionable. Changing the label on the bottle does not convert poison into a harmless beverage. Would that men could see that the exciting currents of sin upon which they so gleefully launch their lives are but carrying them to the cataract (a large waterfall over a precipice) of eternal ruin where the mirth of each gives way to the gloom of doom! (C. Norman Bartlett: Galatians and You: Studies in the Epistle of Paul to the Galatians, 1948)

Deeds (2041) (ergon from ergo = to work) refers to toil as an effort or occupation.

Jamieson comments that

The hidden fleshly principle betrays itself palpably by its works, so that these are not hard to discover, and leave no doubt that they come not from the Spirit.  (Jamieson, Fausset, Brown )

Flesh (4561) (sarx) is used here to refer not to the physical flesh but to that aspect in man which is orientated toward self (self will, self effort, selfish, etc). The flesh then is our fallen nature, inherited from Adam, which is prone to commit sins, is opposed to God and which incessantly  seeks its own ends. Flesh is the urge within us toward total autonomy (self-directing freedom and especially moral independence. It is that aspect of fallen human nature that does not relish the things of God and prefers to get satisfaction from independence, power, prestige, and worldly pleasures. See chart contrasting in the flesh vs in the Spirit

In short, flesh is all that one is separated from God.

Kistemaker quips that

What today is often called “sickness” is by Scripture called “obvious work of the flesh.”  (Hendriksen, W., & Kistemaker, S. J. NT Commentary Set. Exposition of Galatians Baker Book or Logos)

Are (2076) (estin) is in the present tense indicating that these deeds are continually obvious. In other words one can readily discern when they are being "energized" by the flesh rather than the Spirit.

Evident (5318) (phanerós = manifest, visible, conspicuous, from phaino = give light to shine; become visible from phos = light) means visible, apparent or manifest (as opposed to that which is hidden). It stresses what is visible to the sight so that anyone may see. Phaneros pertains to being clearly and easily able to be known. The idea of these deeds or works of the flesh is that they are plain or open, with overtones of being unashamed and blatant. Paul appeals to their common knowledge.  The flesh may be concealed within us but it betrays itself by its own works, so that is recognition is easy.

Vincent phrases it this way...

You have a clearly defined standard by which to decide whether you are led by the Spirit or by the flesh. Each exhibits its peculiar works or fruits.

James Montgomery Boice explains that...

When Paul says that the acts of the flesh are obvious, he does not mean that they are all committed publicly where they may be seen. Some are, some are not. Instead, he means that it is obvious to all that such acts originate with the sinful nature, and not with the nature given believers by God. (Gaebelein, F, Editor: Expositor's Bible Commentary 6-Volume New Testament. Zondervan Publishing)

Steve Zeisler offers some very insightful remarks on the phrase the deeds of the flesh are evident writing that...

The flesh brings us temptations in such attractive guise that it's often difficult to know when we are being tempted to turn our freedom into fleshly indulgence. The flesh disguises its temptations magnificently, but the results are always the same: sin always pays its servants, and the wages of sin is always death. If we are willing to be honest about what is happening to us, if we are willing to look at ourselves as we really are, then we will either see that the flesh is producing its deeds--strife, enmity, immorality, sorcery, drunkenness--or we will see that the Spirit of God is truly producing his fruit in our lives and there is more love, more real joy, greater peace and more self-control than ever before.

In the well-known story of the emperor's new clothes, a foolish emperor is tricked by wily tailors who claim to have made him a suit so beautiful, raiment so glorious that it is absolutely astonishing to behold. When the king looks in the mirror, however, he cannot see these new clothes. In fact, it seems to him that he is in his underwear. But he doesn't admit that because the tailors keep praising his beautiful new clothes. In a big parade everybody in the crowd reacts the same way: they assume there is a problem with them. Finally, one little boy says, "The emperor has no clothes." The bubble is burst, to the embarrassment of the king. The crowd breaks into laughter.

The point that Paul is making here is if we are willing to be honest, if we are willing to look at things as they really are and not hide behind clever tricks, then when we are in the flesh (Ed note: Behaving fleshly or living according to the fleshly impulses) it will be quite obvious to us. Likewise, if the Spirit is bearing His fruit that too will be obvious; it will not be hard to discover. The difficulty is in being honest, in being willing to examine ourselves. The deeds of the flesh, Paul declares, are evident.

I once played in a football game following a torrential downpour. It was a mud bowl. The light was bad. The rain was falling. By the end of the game it was absolutely impossible to tell who was on our team and who was not, because of the mud. When we called plays we didn't know whether we were running into our opponents or into our own team. But in this conflict that Paul is talking about, the apostle says that you can always tell what's going on if you are willing to be honest. The jerseys always are clearly distinguishable. The difficulty for us is in being willing to be honest. People are forever excusing sin by saying, "It's modern, it's scholarly, it's advanced, it's different." A whole litany can be recited as to why a particular activity ought to be put in a "right" category. But Christian honesty must agree that immorality is not changed by being named something else. I may offer all kinds of justification for why I am doing what I am doing, but if at the end of the process I am filled with anger and envy, that is the flesh. "The deeds of the flesh are evident." (See his entire sermon Fight the Good Fight)

C Norman Bartlett organizes this list of vices into...

the following threefold division: (1) sensual works of the flesh, (2) religious works of the flesh, and (3) social works of the flesh. We could classify them as sins of impurity, idolatry, hostility and revelry. In any event, the list of moral offenses here given by the apostle is suggestive merely, and by no means exhaustive. All of us, it is to be feared, are prone to let our freedom from certain types of sins blind us to our bondage to other kinds no less hateful, and perhaps even more hateful, in the sight of the Lord. Are sins of the mind less revolting to Him than those of the flesh?

Adultery, fornication, uncleanness, lasciviousness... Never, perhaps, has there been a day when it was more difficult to live a clean life than at this present time. Appeals to the flesh abound on every hand. Indecency is brazenly flaunted before our eyes. The vileness in our current magazines know no bounds. If it be true that "as goes the home, so goes the nation," then there is grave cause for concern as to the future of our beloved country in the steadily mounting divorce rate and the trail of broken homes from one end of the land to the other. (Ed note: And this was published in 1948! Woe!) Sensual sins of all kinds are frightfully prevalent in all strata of American society. (C. Norman Bartlett: Galatians and You: Studies in the Epistle of Paul to the Galatians, 1948)

Spurgeon comments that...

Any kind of sensual indulgence — whatever it may be — a lustful glance, the cherishing of an unclean desire,— the utterance of a foul expression, all this is condemned, as well as the overt acts of adultery and fornication.

IMMORALITY

Immorality (4202)(porneia from porneúo = commit fornication or any sexual sin) originally referred to any excessive behavior or lack of restraint, but eventually became associated with sexual excess and indulgence, of every kind of extramarital, unlawful, or unnatural sexual intercourse.

Immorality was scarcely reckoned as a sin in the opinion of most of the pagan Gentiles in Paul's day (sounds very familiar to our modern amoral culture!) And so Paul begins with immorality, not because it was worse than the fourteen other vices, but because immorality was the most open and shameless vice in the Greek and Roman "culture".

Porneia originally was used especially to describe the practice of consorting with prostitutes (porneis = “prostitute”) and eventually came to mean “habitual immorality.” Porneia is the opposite of the Greek word enkrateia/egkrateia (literally "holding oneself in"), which usually referred to sexual self-control (see Acts 24:25)

As an aside, porneia refers primarily to sins of the flesh, but those sins can never be divorced from the sins of the mind or heart, because all sin is related. Sin in one area always makes us more susceptible to sin in other areas (don't be deceived). No where does Scripture sanction the commitment of any form of extramarital sexual activity...a far cry from our modern American culture!

Impurity (167) (akatharsia from a = without + kathairo = cleanse) is a broad term referring to moral uncleanness in thought, word, and deed. It describes a state of moral impurity, especially sexual sin. The term akatharsia refers to filth or refuse. Akatharsia  is moral defilement whether in the form of lust or profligate living. It is a state of moral impurity related to thought, action or speech.

Akatharsia describes a filthiness of heart and mind (so it is internal as compared to anomia discussed below) that makes the person defiled. The unclean person sees dirt in everything. The word akatharsia suggests especially that it defiles its participants, making them unusable for sacred purpose. While akatharsia includes sexual sin, it comes from a wider Septuagint (Greek translation of the Hebrew OT) usage where “unclean” could refer to anything that made a person unfit to go to the temple and appear before God. In a medical sense Hippocrates used this word to describe an infected, oozing wound with pus and crusty impurities that gather around the sore or wound. What is “impure” is filthy and repulsive, especially to God. Akatharsia was a general term often used of decaying matter, like the contents of a grave. In short akatharsia describes any excessive behavior or lack of restraint and speaks more of an internal disposition. An immoral filthiness on the inside whereas the lawless acts of ''immorality'' are on the outside.

SENSUALITY

Sensuality (766) (aselgeia from aselges = licentious <> a = negates next word + selges = continent) originally referred to any excess or lack of restraint but came to convey the idea of shameless excess and the absence of restraint, especially with sexual excess. Thus like koite, aselgeia was used almost exclusively of especially lewd sexual immorality, of uninhibited and unabashed lasciviousness. It refers to the kind of sexual debauchery and abandonment that characterizes much of modern society and that is often flaunted almost as a badge of distinction! Aselgeia refers to uninhibited sexual indulgence without shame and without concern for what others think or how they may be affected (or infected). It describes  absence of restraint and reckless sinning with little sense of shame even though it shocks public civility because of its lack of regard for society.

The Greeks defined aselgeia as “a disposition of soul that resents all discipline,” as “a spirit that acknowledges no restraints, dares whatsoever its caprice and wanton insolence may suggest.”

C Norman Bartlett writes that...

MAN MADE GODS...
GOD MADE MEN

Idolatry... That man is incurably religious and will worship false gods rather than none at all, the non-Christian religions of the world abundantly prove. But in so-called Christian lands hosts of men and women, who would never sink to such depths of ignorance and superstition as to bow down to images of wood and stone, are nevertheless worshipers of idols - wealth, pleasure, power, fame. These they set upon the throne of their hearts which none but God has a right to occupy. How much better off the world would be if man-made gods were to give way to God-made men! (C. Norman Bartlett: Galatians and You: Studies in the Epistle of Paul to the Galatians, 1948)

IDOLATRY

Idolatry (1495) (eidololatreia from eidolon