Demas was a friend and co-worker of Paul. He worked with Paul while Paul was in Rome between A.D. 61-63. He is mentioned in the greetings sent by Paul in the book of Colossians and the book of Philemon. But by the end of Paul's ministry, Demas deserts Paul, as the apostle faced execution in Rome (about AD 68).
Demas may be a diminutive form of "Demetrius", or perhaps a derivative of the Greek word δῆμος. If the former, then Demas's family probably had followed the goddess Demeter (or Ceres). If the latter, then his name may mean simply "of the people". The common usage of Demetrius probably points to the name being a "nickname" to reflect a new life in Christianity.
Background and Early Life
Demas (born Demetrius?) was probably a native of Thessalonica, the capital of the Roman province of Macedonia. The city was a major metropolitan area with a population of about 200,000. Since he is found with Paul at Rome during his first imprisonment there, it can be deduced that he joined Paul on his second missionary journey when he established the church in that city.
Though there was a large Jewish population there, it was Gentiles like Demas that showed the most interest in the gospel in those turbulous times. Since he is listed with Luke in Paul's letters, it may have been the physician who first taught Demas about Jesus. This would have been about AD 50. If this was the case, and with Demas leaving Paul in 68, it is easy to see him becoming enamored as a young man (about 25) but disappointed after over a decade of ministry.
Taking this into account, Demas was probably born in the reign of Tiberius Caesar of Rome. The city was much like others its size in that time. The coming of a Jewish preacher was not unusual in those days, though the talk of the Messiah was rare. Named Demetrius by his Greek parents, it is likely that his family was loyal to the goddess Demeter, "mother earth" who was said to rule the seasons and the crops. The words of Jesus concerning resurrection being like a seed planted in the ground in order to be "reborn" as fruitful crop must have resonated with him.
Ministry and Apostasy
Being drawn from city life to a life of travel, Demas accompanied Paul and Luke on journeys all across the Roman Empire. He fled his hometown, and probably his family, when the Jews mistreated the Apostle in the early days. From town to town, he saw the persecution that both the Jews and the Romans dealt to the new sect of Jews known as "the Way" and then as Christians. However, when Paul faced execution in Rome on the second imprisonment there, he could only say that Luke was with him. Demas had run from the danger of execution -- guilt by association -- preferring to seek a safer way in the secular world. Since we cannot know from the Bible what became of his, Demas becomes a cautionary tale of "loving this present age" above the glorious age to come -- Heaven and eventual Resurrection.