For freedom Christ has set us free; stand firm therefore, and do not submit again to a yoke of slavery. (Gal. 5:1)
For you were called to freedom, brothers. Only do not use your freedom as an opportunity for the flesh, but through love serve one another. For the whole law is fulfilled in one word: “You shall love your neighbor as yourself.” But if you bite and devour one another, watch out that you are not consumed by one another.
But I say, walk by the Spirit, and you will not gratify the desires of the flesh. For the desires of the flesh are against the Spirit, and the desires of the Spirit are against the flesh, for these are opposed to each other, to keep you from doing the things you want to do. But if you are led by the Spirit, you are not under the law. Now the works of the flesh are evident: sexual immorality, impurity, sensuality, idolatry, sorcery, enmity, strife, jealousy, fits of anger, rivalries, dissensions, divisions, envy, drunkenness, orgies, and things like these. I warn you, as I warned you before, that those who do such things will not inherit the kingdom of God. But the fruit of the Spirit is love, joy, peace, patience, kindness, goodness, faithfulness, gentleness, self-control; against such things there is no law. And those who belong to Christ Jesus have crucified the flesh with its passions and desires.
If we live by the Spirit, let us also walk by the Spirit. Let us not become conceited, provoking one another, envying one another. (Gal. 5: 13-26)
As we come to the end of our look through the book of Galatians on the topic of Law and Gospel (of which I have nowhere come close to exegeting it in detail — those who desire to have a more detailed exegesis can consult Martin Luther's Commentary on Galatians for an excellent treatment of this epistle), let us finish with a look at the practical implications of this topic for Christian living.
Previously, we have shown that the idea of the Law being the schoolmaster or guardian is a guard against the heresy of Antinomianism. Even when Paul was focused on condemning Legalism and works-righteousness in the Epistle to the Galatians, he did not for once give any leeway to its opposite error, Antinomianism. Rather the Law still had value in Paul's eyes, and in the sight of God too, though not for salvation through our justification before God.
In the passage further down in Gal. 5, Paul approached the Christian Life from a different point of view. Having destroyed the Law as an instrument of salvation, Paul did not attempt to set forth a new law for Christians based upon the Gospel for obedience. For doing so would not only confuse his audience and remove the force of his previously strong denunciation against Legalism and works-righteousness, but he did not have to do so at all. After all, the important thing in the Mosaic Covenant was never the letter (which Paul denounced strongly), but the spirit behind the letter of the Law (cf Deut. 10:12; Ex. 34:5 - note especially its context). The letter of the Mosaic Law was the "scaffolding" necessary to point towards its inner reality, the spirit of the Law, which is now being fully revealed in the New Covenant.
Paul's manner of approaching the topic of Christian living therefore went straight to the heart of the issue — the spirit of the Law, without using those terms as such since the terminology is not that important. This has the advantage of not needlessly causing confusion by using the term "Law" in more than one sense also. We can however see that this is what Paul was getting at as seen in Gal. 5:14, in which Paul states that the Law is fulfilled in the commandment to love our neighbor as ourselves, thus in this case focusing on the horizontal aspect of Christian living. Like Jesus who mentioned that first in response to a question from the Pharisees (Mt. 22:35-40), the essence of the Law or the spirit of the Law is here put forward as the way of living the Christian life. Christian liberty therefore is to walk in the Spirit and not by the letter (Legalism), or by the flesh (Antinomianism) (Gal. 5:13, 16)
As for living the Christian life, Paul uses therefore comes from the direction of the Spirit- flesh divide to convey the idea of the spirit of the Law. In Gal. 5:17, Paul depicts the both of them at war against each other. After adding a reminder to be led by the Spirit and not by the letter of the law (Gal. 5:18), Paul waded in and showed us the way of Christian living. We are not to indulge in the works of the Flesh in any shape reformed, of which an entire list of sins are given in Gal. 5:19-21. What is shocking here given the theme of Christian liberty is that those who practice such things are stated as not inheriting the Kingdom of God (Gal. 5:21ff), which means they would not be saved. But we do know that Paul is not advocating works salvation here since he has already denounced it in the previous four chapters, so what is he getting at? In light of the Spirit/flesh dualism stated earlier in Gal. 5:17, which parallels the faith/works dualism in Gal. 3:12a, Paul is here suggesting that walking according to the flesh is evidence that one is not walking according to the Spirit and therefore not saved. In other words, if we are saved, we will walk according to the Spirit, and then we will not produce bad fruit. And therefore producing bad fruit would means that we are not walking according to the Spirit, and therefore not saved (Modus Tollens: If p, then q. ~q. → ~p)
In contrast to the evil fruit of an unregenerate heart that does not walk according to the Spirit, the Scripture shows us the fruit (singular) of the Spirit which all believers will have in an ever-increasing manner as we walk in the Spirit: love, joy, peace, patience, kindness, goodness, faithfulness, gentleness, self-control. (Gal. 5:22a). Switching between the Spirit/flesh and the faith/law dualisms, Paul declared that there is no law [letter] operative on the things of the Spirit (Gal. 5:22b). Rather, Christians neither live according to the [letter of the] Law nor the flesh, but according to the Spirit [of and behind the law].
And let us not grow weary of doing good, for in due season we will reap, if we do not give up. So then, as we have opportunity, let us do good to everyone, and especially to those who are of the household of faith. (Gal. 6:9-10)
As Paul wraps up the Epistle to the Galatians proper, Paul exhorts the Galatian Christians to walk by the Spirit as they have lived by the Spirit (Gal. 5:25), of which examples that they are not to be conceited, provocative or envious of each other were given (Gal. 5:26). Good works therefore as designed for believers (Eph. 2:10) is nothing more than living out the Christian life by the Spirit. We are all, like the Galatian Christians whom Paul addressed, exhorted to do good to everyone, especially to our fellow brothers and sisters in the Lord; the household of faith (Gal. 6:10).
With this, let us conclude and see the relevance of the epistle of the Galatians to all of us especially to the modern movements of our day.
[to be concluded]
 C. Matthew McMahon, A Simple Overview of Covenant Theology (Puritan Publications, New Lenox, IL, USA, 2005), p. 58