Paul starts his second missionary journey, with fellow evangelist Silas, from his hometown of Tarsus. They travel west to the regions of Galatia and Phrygia spreading the gospel. Along the way they meet Timothy, who will eventually become Paul's most trusted friend. The three men continue to travel west to Antioch in Pisidia. The group then wants to continue westward to spread the truth in the area around Asia proper but is hindered (Acts 16:6).
Stopped from preaching in the western part of Asia Minor, Paul and company travel northwest to the province of Mysia. The group then seeks to go in a north-easterly direction toward the province of Bithynia but again have their plans thwarted (Acts 16;7). Perplexed at what to do next, the group makes their way to the port city of Troas. It is there that the apostle sees a vision of where he is needed the most.
And a vision appeared to Paul during the night. A certain man of Macedonia was standing, beseeching him and saying, "Come over to Macedonia and help us." And after he had seen the vision, we immediately sought to go into Macedonia, concluding that the Lord had called us to preach the gospel to them. (Acts 16:9 - 10, HBFV).
The burden Saul would have to bear was the trials, troubles and tribulations he would have to experience as one of God's chosen vessels to fulfill his will (Acts 9:16). His threefold commission was fulfilled by his journeys to Asia Minor, Macedonia and Greece, which laid the foundation of the New Testament church among the Gentiles. During this time Paul also preached Christ to the Jews living in these Gentile regions.
In fulfillment of his great commission to testify to the children of Israel, Paul also wrote the epistle to the Hebrews, which was sent to the twelve tribes. At the end of his third missionary journey, he witnessed to the Jews at Jerusalem, to Governors Felix and Festus, and to King Agrippa. On his fourth journey, he witnessed before Caesar at Rome and thus fulfilled every part of the commission that Christ had given him.