Earlier Paul has received guidance and encouragement in visions from the Lord (9:12; 16:9-10). Now the Lord appears to him at night again, with a threefold command attached to a threefold promise, all expressed in biblical language (Deut 31:6; Josh 1:5; Is 41:10; 43:5; Jer 1:7-9):

Do not be afraid (literally, "Stop being afraid")/I am with you

Keep on speaking/No one is going to attack and harm you

Do not be (literally, "become") silent/Because I have many people

in this city

For Paul—or for us—to be afraid is to doubt the last promise of the risen Lord (Mt 28:20). Though Paul has territorially moved beyond the Macedonian call (16:9-10), the Lord is here to guide, telling him to keep on speaking. He promises that no one will attack Paul to harm him (see fulfillment of this in 18:12-17; NIV turns the purpose or result expression into a parallel promise: to attack and harm). Persecution would aim to stop the freely proclaimed, life-changing gospel message (compare 4:18-20; 5:18-20, 28-29; 16:21; 17:7, 13). Therefore Paul is not to become silent. The Lord has already chosen many people (see comment at 15:14) for his own in this city. The Lord's predestination (13:48) not only guarantees a fruitful ministry but demands that Paul responsibly fulfill his obligation to witness. And that he does, teaching . . . the word of God in Corinth for a year and a half.

In light of the vision of Revelation 5:9-10 and 7:9-10—"a great multitude that no one could count, from every nation, tribe, people and language, standing before the throne and in front of the Lamb"—it is right for us today to claim the promises and obey the commands of Acts 18:9-10 for the eleven thousand people groups that have yet to hear the gospel.