Based on the traditional view that 2 Timothy was Paul's final epistle, chapter 4 mentions (v. 10) about how Demas, formerly considered a "fellow worker", had deserted him for Thessalonica, "having loved this present world". In sharp contrast to his dispute with Barnabas over Mark (Acts 15:37–40), which resulted in the two parting ways, Paul now considered Mark to be "profitable to the ministry" (v. 11). The chapter also features the only biblical mention of Linus (v. 21), who in Catholic tradition is listed as Peter's immediate successor as Bishop of Rome.