Why was it such a heartache for Paul that the Asian churches turned away from him?
It grieved Paul because he had poured out his life and suffered greatly to plant numerous churches in Asia Minor, only to see those believers turn away from his gospel by the time he was martyred. Their rejection of the truth he had sacrificially brought them made their abandonment a deep personal heartache.
Les explains that the Asia in view is New Testament Asia Minor, the area of western Turkey, where Paul had started many churches in towns such as Thyatira, Pergamos, and Smyrna. By the time Paul was martyred, those churches had already turned away from his gospel. Les notes he does not know exactly in which way they turned away, but the heartache was that Paul had spent so much and poured out his life, yet those people turned their back on him. The results seem evident: none of those little cities are left anymore, while many areas in Greece are still valid—Philippi remains a seaport, Athens remains valid, and Corinth has another city nearby. Western Turkey, by contrast, faded off the scene. Paul had suffered so much to get the gospel to these Gentiles, making their abandonment deeply painful.