Acts 18:9

And the Lord said unto Paul in the night by a vision, Be not afraid, but speak and hold not thy peace: for I am with thee, and no man shall set on thee to harm thee: for I have much people in this city.

A vision ... The Lord repeatedly appeared to Paul to strengthen and encourage him in his proclamation of the truth.

No ... man shall harm thee ... Almost at once, there would occur the most remarkable providence on behalf of Paul, in that those who sought to harm him were themselves dispersed and one of them beaten in the presence of Gallio. This promise of the Lord did not mean that men would not assault Paul, but that they would be unsuccessful in their efforts to thwart his preaching.

I have much people in this city ... Alexander Campbell thought this referred merely to the size of the city,[18] but it would appear more logical to view the Lord's statement as meaning: "That there were much people, not yet saved, but who would accept the gospel when they heard it."[19] Therefore, we view this as a promise that Paul would convert many souls in Corinth.

[18] Alexander Campbell, op. cit., p. 123.

[19] H. Leo Boles, op. cit., p. 289.