Acts 19:8 ¶ And he went into the synagogue and spoke boldly for three months, reasoning and persuading concerning the things of the kingdom of God.
Paul had a mission in Ephesus, to plant a church that would effect all of Asia Minor (modern day Turkey). He knew the key to Asia Minor was Ephesus, a major city in that day that was known for its idolatry and moral depravity (it’s funny but those things always go together). Paul gathered a small group of believers and got them baptized in the Holy Spirit. Next he began to have daily meetings. Can you imagine, for the next two years Paul met with the church daily (tradition says from 11-4) preaching on the kingdom of God. What does that mean, preaching the kingdom of God? Here is how John Piper describes it.
“Since God’s purpose for the world is to save a people for himself and renew the world for that people, his kingly rule implies a saving and a redeeming activity on their behalf. This is why the coming of the kingdom in the New Testament is called good news.
In and through Jesus, God, the king, is coming in a way — a new way — into the world to establish his saving rule. First, in the hearts of his people and in their relationships by triumphing over sin, Satan, and death. Then by the exercise of his reign, gathering a people for himself in congregations that live as citizens of a new allegiance of the kingdom — not of this world. Then Christ comes a second time and completes the reign by establishing a new heavens and a new earth.”
So the message of the kingdom deals with a spiritual kingdom ruled by King Jesus Himself. The message of this kingdom is redemption. This includes the work of the cross and the Holy Spirit. Our sins are forgiven through the power of the blood of Jesus poured out at the cross. We are made alive to this kingdom life by the regeneration and renewal of the Holy Spirit. Remember what Paul said in Romans 14:17 “for the kingdom of God is not eating and drinking, but righteousness and peace and joy in the Holy Spirit”.
This shows us what Paul’s plan was in Ephesus, to preach Christ and harvest souls who had been bound by idolatry and sinful behavior and to provide an atmosphere for them to saturate in the presence of the Holy Spirit until their lives radiated the beauty of the kingdom of God. This is what church is intended to be, a dwelling place for the Holy Spirit that impacts the city that church is in.