Romans 16:21 - Matthew Poole's English Annotations on the Holy Bible

As before he saluted divers persons himself, so now he sendeth the salutation of others to the church of Rome. This he doth to show the mutual amity and love that is and ought to be between Christians; though they are divided in respect of place, yet not in respect of affection and goodwill. He begins with Timotheus, or Timothy, whom he calls his work-fellow, or fellow helper, viz. in preaching and propagating the gospel of Christ. This shows the humility of the apostle, that he dignifies so young a man with this title. This is he to whom he wrote afterwards two Epistles; you may read more of him, Acts 16:1-7, and elsewhere. Lucius: Origen and some others are of opinion that this was Luke the evangelist, who was the inseparable companion of the apostle Paul, and was with him about this very time, as appears by Acts 20:5; and here he is called Lucius, according to the Roman inflexion. Others think that this was Lucius of Cyrene, of whom you read, Acts 23:1. Jason; this was Paul's host at Thessalonica, Acts 17:5,7; the same, as some think, that is called Secundus, Acts 20:4, the one being his Hebrew, the other his Roman name. Sosipater; the same that is called Sopater of Berea, in Acts 20:4. My kinsmen: see Romans 16:7.