It seems inevitable that false teachers who trouble the church will reveal themselves as unstable and inconsistent. Unconcerned with faithfully representing the entire scope of Scripture, purveyors of error lack a consistent standard, so they end up with a fundamentally incoherent theology and way of life. We see this in the false teachers in Corinth, who went from criticizing Paul’s ministry for what they perceived to be its lack of effectiveness to taking credit for his labors and attempting to build on the foundation he had laid (2 Cor. 10:1–16). Only a divided mind undisciplined by the consistent truth of God’s Word could produce such confusion.
The Apostle has countered the false apostles in the Corinthian church by saying that unlike them, he will boast not in the work of others but only in his call and in his faithful fulfillment of it (vv. 13–16). Apparently, Paul was not quick to do this, but he was forced into it to show the Corinthians how the true way of ministry according to the gospel is fundamentally at odds with false teaching. In any case, the Apostle’s willingness to boast indicates that there is a kind of boasting that can be appropriate in the Christian life.
What does such boasting look like? Paul tells us in today’s passage. Paraphrasing Jeremiah 9:24, the Apostle says that proper boasting consists of boasting in the Lord (2 Cor. 10:17). Essentially, Paul tells us that any boasting he is doing in his faithfulness is really boasting in the Lord because the Lord gave him his ministry and the Lord makes it effective. This fits well with the Jeremiah text because the prophet there stresses God’s work of steadfast love, justice, and righteousness in all the earth, and it also matches Paul’s teaching in 1 Corinthians 3:5–8 that in the work of the church, the Lord gives the growth. Our labors are vital, but unless God blesses and works through them, they are useless. As we look to our own faithfulness, we must recognize that the Lord is the source and sustainer of our service.
All other boasting is the self-commendation that Paul labels pointless in 2 Corinthians 10:18. Only the Lord’s approval is a sure foundation. Matthew Henry writes: “Of all flattery, self-flattery is the worst, and self-applause is seldom any better than self-flattery and self-deceit. At the best, self-commendation is no praise, and it is oftentimes as foolish and vain as it is proud; therefore, instead of praising or commending ourselves, we should strive to approve ourselves to God, and his approbation will be our best commendation.”