1 Corinthians 16:9

Opened. Paul referred to the unusual opportunities presented to him at Ephesus for the preaching of the gospel, as the reason why he wished to remain there for some time instead of proceeding at once to Macedonia and Corinth (see vs. 7, 8). Ephesus was an important center of pagan worship in the Roman province of Asia, the goddess Diana (or Artemis) being the principal deity (see on Acts 19:24). In this city, almost wholly given over to idolatry, superstition, and vice, God manifested His power through Paul for the conversion of sinners and the confusion of the adversary (see Acts 19:8-12, 18-20).

Adversaries. When opposition arose at Ephesus, Paul did not leave the city, but worked all the more earnestly for the advancement of the kingdom of God. Such opposition may generally be regarded as evidence that Satan is alarmed at the threat to his dominion over the souls of men, and as an indication that the Spirit of God is at work.