God directed the missionaries’ travels: The Holy Spirit had prevented them from proceeding westward into the province of Asia, the Spirit of Jesus did not allow them to go north to Bithynia, and then Paul had a vision calling them to go northwest over the Aegean Sea to Macedonia.
In the book of Acts, God's Spirit guided his servants in many ways, including:
advice from other believers (compare 15:29),
understanding through Scripture (28:25–27), and
prophecy (11:28).
The Holy Spirit's guidance helped them accomplish their mission to be Christ's witnesses (1:8; see also 4:8, 31; 11:24; 13:9).