Paul often uses benedictions for personal commendations, often to solicit support for a colleague. The apostle's introduction of Tychicus to the Colossians carries considerable weight. He is more than a courier of personal regard—someone sent by Paul to field questions about his imprisonment so that the believers can pray more effectively for him (Wright 1987:155). The titles Paul gives Tychicus, dear brother, a faithful minister and fellow servant, suggest a role more important than that of a messenger. He was, in O'Brien's words, "a particularly valued colleague" (1982:247). In fact, the title faithful minister (diakonos, literally "servant," from which we derive "deacon") is used earlier to describe the ministry of both Epaphras (1:7) and Paul himself (1:23). Moreover, the title fellow servant (syndoulos) is used earlier (1:7) to describe Epaphras as one who participates equally with Paul in the Gentile mission. In effect, Tychicus is Paul's own designate to continue the ministry, at least at Colosse, during his imprisonment. Epaphras would have been the natural person for this ministry, since he first brought the gospel to Colosse; however, apparently his relationship with the Colossians is troubled and requires Paul's intervention (4:12-13).
Because of the various interruptions during his ministry (including imprisonment), Paul was unable to visit many Gentile congregations in person even though this was his desire. In Romans, for example, Paul repeats his desire to visit the Christian congregations in the world's most important city in order to "impart to you some spiritual gift to make you strong" (Rom 1:11; compare 15:23-4). Like the Colossian believers, those in Rome had never profited from the apostle's personal visit, a time when Paul could minister to them directly and they could benefit from his apostolic persona and gifts.
Paul's constant references in his letters to past and future visits are expressions of his apostolic authority. The gifts that Christ had given him (see Rom 1:5) have transformed him into a conduit of eschatological power, capable of empowering others to resist evil and grow in holiness, thereby preparing for the Lord's return. When he was unable to visit congregations in person, Paul sent substitutes (both people and letters) through which his apostolic ministry could continue to have its powerful effect (Funk 1967:249-68). Tychicus is one such substitute, Timothy is another (Phil 2:19; 1 Thess 3:6), and this very letter is a third. In this case, the apostle is "in chains" and unable to convey the gift of his apostleship to the Colossian believers in person. Because their faith is threatened by false teaching, he sends Tychicus as minister and servant to encourage [their] hearts—the very purpose Paul has assigned to himself (2:2).
This point is highlighted by the chiastic pattern of the text itself. Recall that a chiasmus is a literary device that arranges words and ideas into two parallel and inverted passages, with an odd member placed at the vertex, where the two passages intersect (ABCDC'B'A'). The odd phrase found at the vertex (D) helps the reader locate the passage's principal idea. Consider verses 7-9 in this light:
A Tychicus will tell you all the news about me (v. 7a).
B He is a dear brother, a faithful minister and fellow servant in the Lord (v. 7b).
C I am sending him to you for the express purpose that you may know about our circumstances (v. 8a)
D and that he may encourage your hearts (v. 8b).
C' He is coming with Onesimus (v. 9a),
B' our faithful and dear brother, who is one of you (v. 9b).
A' They will tell you everything that is happening here (9c).
The chiastic shape helps us to identify the most important ingredient in the instructions Paul sends to the Colossians: that [Tychicus] may encourage your hearts. Paul's chief interest is that his ministry continue through Tychicus during his imprisonment (see Lohse 1971:171). The chiasmus also subordinates Onesimus to Tychicus, for it is the latter who is central to Paul's plans and additionally is called faithful minister. The credential added to Onesimus, who is one of you (4:9), suggests that his task is to help Tychicus gain entry into this Colossian community.