Acts pulls the curtain back for us a few times to see how it is that God is working out is plan. Just as explained in Ephesians 1, “I chose you before the foundations of the world”, God works out in Acts as he tells Paul, “I have many in this city” though they do not yet believe. And we see the means God ordains to draw them to himself which is the proclamation of the gospel.
And the Lord said to Paul one night in a vision, “Do not be afraid, but go on speaking and do not be silent, for I am with you, and no one will attack you to harm you, for I have many in this city who are my people.” (Acts 18:9-10 ESV)
We must believe that God has set apart who are his already so that we can be confident in the work of evangelism, AND we must believe that it is our preaching that God has ordained as the means of bringing his own into faith. Otherwise our own faithfulness in going with the gospel is out of whack. We must see the urgency and the significance of our going (it is God’s ordained means), but we must also see that those who respond do so because they belong to the Lord and not because we were so marvelously persuasive. God’s word always accomplishes it’s purpose. This is both a convicting doctrine (as it highlights the high role of proclamation, which involves preaching and evangelism), and a freeing doctrine (as the results of the proclamation come from the Lord).
McCheyne’s Bible Reading Plan: Jg 14, Acts 18, Jer 27, Mk 13