In Galatians 5 and verse 16, we find a verse that is too often misinterpreted and misapplied. We make those errors because we fail to consider the context of that powerful and liberating verse. The proper interpretation and application of this verse can liberate the believer from the burden that teachers and preachers and sometimes we ourselves put on us. It simply doesn't say what we think it says.
"I say then: Walk in the Spirit, and you shall not fulfill the lust of the flesh."
Doesn't that sound like if we "walk in the Spirit" we will be free from sin? Doesn't that sound like a guarantee that walking in the Spirit can bring us to the place where we will sin no more? Well, it says no such thing. It is not guaranteeing us that we can be free from lust.
First, look at the context. See the word "then?" It keeps us connected to what Paul has been saying up to this point. And what Paul has been saying is that justification is by grace alone, through faith alone, in Christ alone, by the hearing of the gospel alone. Our justification, the act of God alone whereby He proclaims us right with Him, righteous, is not based on our keeping the law or on any supposed good works that we may think we have done, but solely on His gracious and finished work of redeeming us by the blood of Christ and His bringing us to faith in Christ (Jn. 6:44; 2 Thess. 2:13-14).
And what was the problem in Galatia? The Galatian believers (and fence straddlers) had been told by those whom we know as the "Judaziers" that if they wanted to be truly justified they must believe in Jesus AND keep the law of Moses; they had to now be circumcised.
Their argument centered around Abraham. Abraham was circumcised. Circumcision was the sign and seal of the covenant. All Jewish males had to be circumcised. Gentiles must become sons of Abraham by following his example in circumcision. It's the only way to be truly justified before God. This teaching amounts to a false gospel, a "different gospel, which is not another" and is a damnable heresy (1:6-9). The remaining words of this letter argue for justification by faith alone.
I have heard pastors (modern day Judaizers) say from the pulpit that if you aren't tithing, you aren't saved. It is a common heresy in Protestant and evangelical churches; it is a different gospel. It is no less damnable than telling believers that they must be circumcised. It is preaching justification by works. And those who buy into it are no less culpable (5:1-4).
The unregenerate in the visible church love having something to do in order to assure their salvation. Believers, those who are truly born again but ignorant find the you-must-tithe-in-order-to-be-saved doctrine appealing as well. Both the saved and the unsaved need to hear the message of Galatians lest the gospel be lost (2:1-5).
Second, "then" points us back to verse 14 and a particular word that connects us to all that Paul has been arguing thus far, "For all the law is fulfilled in one word, even in this: 'You shall love your neighbor as yourself." No, it's not the word "love;" it's the word "law."
Love certainly is essential in the Christian's life. And love is the solution to the problem Paul addressed in verses 13-15. But the one central theme of this letter, as I stated above, is how one is justified. "All the law is fulfilled in one word, even in this 'You shall love your neighbor as yourself."
Remember that this is God's law, not man's. Paul has already said that no man, Jew or Gentile, can be justified by keeping the law (2:11-21). He says here in 5:14 to the members of the churches in Galatia that all the law as one who has been justified by grace through faith is fulfilled by loving your neighbor as yourself. The apostle of grace isn't saying that one is justified by loving one's neighbor, but rather if you really want to do something lawful, then try doing that by serving one another in love.
We who have been justified by the grace of God who brought us to faith in Jesus Christ are to love our neighbors. But our loving our neighbors isn't what makes us right with God, it is the result of our having been justified.