The first mention of Silas is in Acts 13. Paul and Barnabas went on a missionary journey (Acts 13:1-5), taking with them John Mark, who (for unspecified reasons) parted from them and went home in the middle of the journey (Acts 13:13). Paul and Barnabas completed their mission and returned to Antioch after having made many Gentile converts on their mission. The question arose whether a Gentile could become a Christian without also becoming a Jew, being circumcised if male, and undertaking to observe the Law of Moses (Acts 15:1).
The congregation at Antioch referred the question to the Apostles at Jerusalem, and Paul and Barnabas went to Jerusalem to present their case. A council of apostles and elders at Jerusalem judged that, with a few specified exceptions, the Law of Moses was not to be imposed on Gentile Christians, and they sent two men from Jerusalem back to Antioch with Paul and Barnabas to convey their reply. The men were Judas Barsabbas and Silas (Acts 15:22).
Eventually Paul and Barnabas undertook to again visit the congregations they had founded on their previous journey, and Barnabas wished to take John Mark with them. Paul thought this unwise, and so they determined to travel separately, Barnabas taking Mark, and Paul taking Silas (Acts 15:36-40). Paul and Silas (joined in progress by Timothy and by Luke) went through part of what is now Turkey and then crossed over into Europe and preached at Philippi. (Paul's Second Journey) Thereafter they went on to Thessalonica and Berea, finding themselves at the center of riots in each place (Acts 17:1-13). Paul went on to Athens and thence to Corinth, and was soon joined there by Silas and Timothy (Acts 18:5), this being the last we hear of Silas.
The name "Silas" is a shortened form of "Silvanus", and the Silvanus to whom Paul refers in his writings to the Corinthians (2 Corinthians 1:19) and the Thessalonians (1 Thessalonians 1:1; 2 Th 1:1) is almost certainly the Silas of Acts. Also, individual was likely the same as the Silvanus who carried the Apostle Peter's first letter (1 Peter 5:12) to its scattered recipients.
Further details of the life of Silas are not known, but he has customarily been honored as a martyr.
