After Paul cautioned the Galatian believers not to use their liberty as an excuse to sin, he continued by discussing how the believers should serve one another in love.
Galatians 5:14-26 (KJV)
For all the law is fulfilled in one word, even in this; Thou shalt love thy neighbour as thyself.
But if ye bite and devour one another, take heed that ye be not consumed one of another.
This I say then, Walk in the Spirit, and ye shall not fulfil the lust of the flesh.
For the flesh lusteth against the Spirit, and the Spirit against the flesh: and these are contrary the one to the other: so that ye cannot do the things that ye would.
But if ye be led of the Spirit, ye are not under the law.
Now the works of the flesh are manifest, which are these; Adultery, fornication, uncleanness, lasciviousness,
Idolatry, witchcraft, hatred, variance, emulations, wrath, strife, seditions, heresies,
Envyings, murders, drunkenness, revellings, and such like: of the which I tell you before, as I have also told you in time past, that they which do such things shall not inherit the kingdom of God.
But the fruit of the Spirit is love, joy, peace, longsuffering, gentleness, goodness, faith,
Meekness, temperance: against such there is no law.
And they that are Christ's have crucified the flesh with the affections and lusts.
If we live in the Spirit, let us also walk in the Spirit.
Let us not be desirous of vain glory, provoking one another, envying one another.
Paul summarized the law in one statement. "Thou shalt love thy neighbor as thyself." This was not original to Paul. It actually comes from the Old Testament.
Leviticus 19:18 (KJV)
Thou shalt not avenge, nor bear any grudge against the children of thy people, but thou shalt love thy neighbour as thyself: I am the LORD.
The law is also summarized in the same way by Yeshua himself.
Matthew 22:39-40 (KJV)
And the second is like unto it, Thou shalt love thy neighbour as thyself.
On these two commandments hang all the law and the prophets.
Notice also that verse 14 says that the law is fulfilled by the action of loving one's neighbor. According to traditional Christianity the fulfilling of the law by Yeshua's death and resurrection meant that the law no longer needed to be observed. Yet, here, Paul contends that the law is fulfilled by loving one's neighbor. Which is it? Obviously, the traditional understanding of fulfill is incorrect. Fulfilling means that a certain action satisfies the requirements of the law. However, the law continues, it is not ended. Every single time that the believer loves his neighbor the law is fulfilled. In the same way Yeshua did what He came to do, to be the perfect sacrifice for sin. It was a once and for all sacrifice that paid for the penalty of sin and allows believers to trust in what He did and gain eternal life. This doesn't change the requirements of the law, however.
Paul went on to say that if the Galatians bit and devoured one another, they would potentially consume one another (verse 15). Instead of loving each other and fulfilling the law, the Galatians were selfishly acting in ways that hurt each other and by doing so would splinter the group and would harm the unity of the body that God intended they have. Paul then told them in verse 16 to walk in the Spirit so that they would not fulfill the lusts of the flesh. Here Paul was speaking about sinful human nature. We naturally behave in these sinful ways, but through the power of the Holy Spirit we are free from that nature and we can walk in the ways God has decreed. In verse 17 Paul described the "war" that goes on inside of the believer. We still carry the old sinful nature, but we also have the Holy Spirit dwelling within. The desires of each are opposites and in that war we often don't do as we should. Paul reiterates in verse 18, however, that if we are led by the Holy Spirit we are not under the law. Again, this is not referring to obedience to Torah living, that results from our love of God, but the rigid observance of ritual because of some sense that it is the ritual (or even Torah itself) that saves and frees from the sinful nature.
Paul listed the works of the flesh in verses 19-21. They are adultery, fornication, uncleanness, lasciviousness, idolatry, witchcraft, hatred, variance, emulations, wrath, strife, seditions, heresies, envyings, murders, drunkenness, revellings, and like things. Paul's list is remarkably broad, yet, it is certainly not complete. Notice that stealing and lying, for example, are not mentioned, nor are sins like disobeying the Sabbath or food laws mentioned. Paul's list, therefore, is not meant to be a complete list of potential sins. Notice, also, that there is a heavy representation of sexual sins, idolatry, hate related sins, and social sins like drunkenness. Paul ended verse 21 by stating that those who engage in these sins will not inherit the Kingdom of God. This is a sobering fact, but Paul wasn't condemning the believer who "misses the mark" or who falls into sin unintentionally. If this were the case, none of us would be able to claim salvation. Rather, there are those in the body of believers who think that they can continue in sin and will still qualify for salvation. Paul's conclusion was that this was simply not the case. The sins listed may be a representative list of sins that Paul observed or heard about in the body of the Galatian believers. It may also represent those sins that the Galatian believers were likely to engage in.
Verses 22 and 23 are Paul's contrasting list of the fruit of the Spirit, those things that are to be demonstrated in the body of believers. They are love, joy, peace, longsuffering, gentleness, goodness, faith, meekness, and temperance. Against these there are no laws. Again, this was not a detailed list of to do's, but rather a broad list of guidelines to behavior.
In verse 24 Paul concluded his argument with the fact that the believers had crucified their flesh with its affections and lusts. Remember, that Paul was using "flesh" not as the bodies of flesh humans have, but the sinful human nature that all have. When we are born again and we receive the Holy Spirit we are freed from the subjugation of the sinful human nature, so therefore, we should walk in the ways of the Holy Spirit (verse 25). In verse 26 Paul ended by warning the Galatian believers not to seek vain glory (pride in oneself), or to provoke one another, or to envy one another. This verse hearkens back to verse 15 where Paul seemed to imply that the Galatians were doing these very things to each other. Although they truly were believers, they certainly were behaving in ways very much in opposition to God's intent.
When the false teachers came to the fellowship of the Galatians, their introducing the necessity of becoming Jews ritually and following all of the traditions, added to this backbiting behavior, and caused further disunity. Paul was teaching them to go back to the gospel that He had taught them. What about our own congregations, do we exhibit works of the flesh and the backbiting behavior that leads to disunity? There will always be believers who hang onto sin, but if we truly are born of the Spirit and are led by the Holy Spirit, we need to implement the fruit of the Spirit and to banish those works of the flesh that can ensnare us.
As Paul initially summarized, our goal is to serve one another in love and thereby fulfill the law.