A follow-up point to this is that “God had opened a door” for the Gentiles to hear the gospel. If He opens a door for the gospel to be presented to those who have never heard, we must be faithful to go through that door. It is a ‘God’ opportunity! For a further example of how Paul looked for these open doors, see 1 Corinthians 16:8-9 and Jesus’ words in Revelations 3:7.
Be occupied with what God is doing and look for the opportunities that He presents. This will preserve us from striving with our own agendas and seeking glory from men.