Paul is calling for separation. In the immediate context, the separation had to do with the antagonists who troubled the Corinthian church. But the principles that we find in this passage, apply to a broader spectrum than just the specific situation in Corinth. In fact, some would argue, though I don’t agree with them, that Paul didn’t even have the antagonists in mind here. They would argue that he simply had the pagan culture of Corinth in mind.
Believers are called to this kind of separation throughout the history of the church. The fact that Paul can make his argument from Old Testament Scriptures says that this kind of separation has been the responsibility of believers throughout the history of redemption. Wherever salvation has come, God’s people have been called to holiness.
He has appealed for an open heart and this passage reveals his motive for that appeal. He wants them to open their hearts, not only because he loves them, but because he has warnings that need to be heeded. The narrowing of their affections toward the apostle puts them at spiritual risk.