Charles Ellicott Commentary Acts 18:11

"And he dwelt [there] a year and six months, teaching the word of God among them." — Acts 18:11 (ASV)

And he continued there a year and six months. This obviously gave time not only for founding and organizing a Church at Corinth itself, but for work in the neighboring districts, such as the port of Cenchreae, where we find in Romans 16:1 a church duly furnished not only with presbyters and deacons, but with a sisterhood of deaconesses.

The superscription of 2 Corinthians 1:1, “to the Church that is in Corinth and to all the saints that are in all Achaia,” clearly indicates an extension of evangelizing work beyond the limits of the city. The unimpeded progress of this period came to him as an abundant fulfillment of the Lord’s promise, and prepared him for the next persecution when it came.