Paul claimed the freedom to minister in Corinth without receiving financial support from the Corinthians to illustrate his self-sacrificing love for his readers and his critics' selfishness. He digressed from his "foolish"boasting (vv. 1-6) to defend his policy regarding his own financial support (vv. 7-12) and to describe his opponents' true identity (vv. 13-16).
11:7-8 Paul had written that apostles have the right to refrain from working for a living and to live off the gifts of their audience (1 Cor. 9:6, 14). Yet he had made tents in Corinth and had refused to accept gifts from the Corinthians (cf. Acts 18:3; 1 Cor. 9:4-15). This indicated to some in Corinth that he did not believe he was an apostle. The other apostles normally accepted support from the recipients of their ministries, and these false apostles evidently did so consistently.
Paul had expounded God's truth in Corinth without accepting money from his converts there for doing so. He adopted this policy in Corinth and elsewhere because he did not want to burden the people he was currently ministering to. He also did so because he knew there were people who would accuse him of preaching to receive payment. He accepted financial help from other church while not ministering to them directly ("robbed them") so he could serve the Corinthians without taxing them.
11:9 Paul had practiced his trade of leather working (Gr. skenopoios) when he had first arrived in Corinth (Acts 18:3). When Silas and Timothy joined him from Macedonia, Paul stopped this work and devoted all his time to preaching and teaching (Acts 18:5). He apparently did this because these brothers had brought financial gifts with them from the Macedonian churches (cf. Phil. 4:15; 1 Thess. 3:6). Paul's principle was to preach and teach without charging those who benefitted directly from his ministry. This is a good policy in church planting, but it is not normative for a settled pastoral ministry (1 Cor. 9:14; 1 Tim. 5:17-18).258
11:10-12 Paul claimed that he had not sinned in behaving as he had (v. 7). He had not deceived his readers. Rather, as God knew his heart, he had behaved as he had because he loved the Corinthians. Furthermore it was not necessary for him to change his policy of accepting or declining support on the basis of the welfare of those he served. His critics uniformly accepted support. By giving up his right to preach the gospel without cost Paul would have been descending to their level. He also would have enabled his critics to compare themselves with him favorably.
11:13-15 "The moment has come for Paul to drop the veil of irony and to speak in the plainest possible terms in denunciation of these would-be super-apostles' who have invaded his territory in Achaia."259
Paul did not want the Corinthians to associate him with these people because they were counterfeit ambassadors of Christ. It is for this reason that their accusations concerned Paul. They were self-servers who were the true sons of their father Satan, the consummate hypocrite.260They may have been genuine believers. Indeed they appear to have been. Nevertheless in their conduct they were following the example of Satan. They perverted the thinking and misdirected the affections of the Corinthians.261
In our own day when people value toleration so highly and practice it so widely even in the church, we need to learn from Paul's example of calling a spade a spade. The welfare of those under his ministry required him to identify his critics for who they really were. We will serve our generation faithfully if we do the same. We should point out teachers who lead others into error and warn people about them if we want to keep the naive from harm.