During the night Paul had a vision: there stood a man of Macedonia pleading with him and saying, “Come over to Macedonia and help us.” (Acts 16:9)
In the verses just before this Paul and his companions had been met by one closed door after another. They had not set out for Macedonia; it had not even crossed their minds. But the attempt to go to west into Asia (what is now western Turkey) had failed, and the choice then to go into Bythinia (northern Turkey) had been blocked. They keep walking and end up in the port city of Troas near what is now Istanbul. There the unexpected happens.
God is a god of the unexpected. Moses was tending sheep when he stumbled across the burning bush. Jacob grabbed any old rock for a pillow only to find it lay where heaven touched earth. No one expected Joseph to show up again once he had been sold into slavery. Peter was locked securely in prison when an angel set him free. And then there was Mary…
We need to get used to the fact that God will lead us to the unexpected. It can be both courage and comfort when all the doors seem closed.