That's not exactly true. While God did lead Paul where he went to preach, Paul didn't go preach to existing congregations all the time. He preached first in the synagogue but after they rejected, which they typically did, he preached wherever. In Athens he preached in the marketplace, which is where he ran into the Epicureans and the Stoics which is how he ended up at Mars' Hill. God opened one door, which Paul walked through to another door, and the end result is one of the greatest sermons of all time.
Paul constituted churches pretty much wherever he went. The Spirit of God was working in front of him, regenerated His children and preparing them for the gospel, yet they weren't converted church bodies until the gospel arrived by the hands of Paul.
If a preacher is led by God to speak in a public place, he should do so. That's exactly what the apostles did. We should also follow their example and shake the dust off our shoes when they reject the message.
Paul constituted churches pretty much wherever he went. The Spirit of God was working in front of him, regenerated His children and preparing them for the gospel, yet they weren't converted church bodies until the gospel arrived by the hands of Paul.
If a preacher is led by God to speak in a public place, he should do so. That's exactly what the apostles did. We should also follow their example and shake the dust off our shoes when they reject the message.