And a vision appeared to Paul in the night: a man of Macedonia was standing there, urging him and saying, ‘come over to Macedonia and help us.’  (Acts 16:9)

On his return to Galatia, the apostle Paul had planned on expanding his mission to the Roman province of Asia; but receiving an unspecified negative sign sent by the Holy Spirit that barred him from travelling west, he decided to head north to Bithynia and Black Sea coast, only to be prevented again.  Then he was sent a positive sign in the form of a vision, so informing where he was to go.  However, there is good cause to speculate that this was a test for the apostle because, historically, the Macedonians had visited great harm on his people, the Jews and had left a legacy that challenged those who feared God and observed His Holy Law. 

Μακεδονία, Macedonia, was the northern Roman province to the north of Achaia, or Greece. Though to Paul and all Jews, Greeks were interchangeable, Macedonia was not Greece.