Acts 16:10
After Paul had seen the vision, we got ready at once to leave for Macedonia, concluding that God had called us to preach the gospel to them — the shift from they to we (the we sections of Acts begin here) is traditionally interpreted as Luke's joining the missionary party. The inference (sunbibazō, to conclude, assemble) from the vision to the divine call (proskaleō, to invite) suggests apostolic discernment: they recognized the vision as God's directive. The European mission begins.