Ambrosiaster : Paul made it clear that he was staying at Ephesus because he had found hearts there who were thirsting for the grace of God, and in them he could quickly instill the mystery of Christ. But because the devil is always restless and hostile to those who long for God, he adds that his enemies there are many. For the more they sought after the faith, the more there were adversaries who contradicted them and fought against the teaching of the Lord. — COMMENTARY ON PAUL'S EPISTLES