He is mentioned only five times in the New Testament, casually, as though he was of no particular importance. Yet reading between the lines, and noting how close he seemed to be to the Apostle Paul, it may well be concluded that Aristarchus was a stalwart character who played a relatively significant role in the busy missionary activities of the great Apostle.
He is first mentioned in the story of the riot at Ephesus (Acts 19) when, in company with a fellow‑worker, Gaius, he was hurried into the amphitheatre by the irate citizens, angered at the threat posed to their goddess Diana by the faith preached by these men. It is said there that they were Paul’s "companions in travel"; from a reference in Acts 20:4 it emerges that Aristarchus hailed from Thessalonica in Greece. It is likely therefore that the two men first met when Paul came to Thessalonica during the course of his second missionary journey (following the dream of the man calling him to "come over into Macedonia, and help us": Acts 16:9; 17:1), some five or six years previously. Paul’s party at that time included Timothy, Silas, and Luke. It is very possible that before leaving Greece for Ephesus Aristarchus had given up his occupation in Thessalonica and thrown in his lot with the Apostle.
Does this mean that as a completely new convert he was prepared thus to share the itinerant and arduous life of those who travelled with Paul preaching the gospel of the kingdom? It could have been so, but would Paul on the other hand have been likely to accept an untried man, still new in the faith, for so important a duty? In a similar situation he chose and accepted Timothy at Lystra (Acts 16:1) only after the local Christian communities had given him a glowing report as to the young man’s qualities, and he had known the faith long enough to have become reasonably mature. It might well have been that something of the same was the case with Aristarchus. It is true that the church at Thessalonica was founded by Paul on the occasion of his first visit, but the tone of the narrative, "some of them (the Jews) believed...of the devout Greeks a great multitude and of the chief women not a few" (Acts 17:4) seems to indicate a readiness to believe and organise into a community separate from the synagogue which could imply that many of them already knew of and had accepted much of the Christian gospel prior to Paul’s visit, perhaps without separating from the synagogue, and it only needed the coming of the Apostle and the clearer light he could shed on the elements of the faith to induce the formation of the Thessalonian church. It might well have been that one or more citizens of Thessalonica—perhaps Aristarchus himself—had been at Jerusalem on the day of Pentecost and heard the Apostles preach, and taken the news back with them. It is not beyond the bounds of possibility that Aristarchus was already partially instructed in the faith, already a partial believer in Christ, when Paul met him, and that the Apostle, recognising some sterling qualities in this man, invited him a couple of years later to join him. So when the third missionary journey was in progress this stalwart Greek found himself working with Timothy, Silas and Luke.
The next mention of Aristarchus is about a year later. After the riot at Ephesus, Paul had gone back to Greece, revisiting the churches he had founded during his second missionary journey, and after six months or so set out for what was destined to be his last visit to Jerusalem, from where he was sent to Rome. Quite a party accompanied him on this occasion, and Aristarchus was one of the party. (Acts 20:4) Most of them left Paul at various points on the ensuing journey, in the interests of various commissions and duties, but when at last Paul arrived at Jerusalem Aristarchus was still with him, together with Luke and Trophimus at least. He had now been a companion in travel to Paul for something like five years.
There followed Paul’s two years imprisonment at Caesarea under Felix and then his voyage to Rome. Aristarchus was still with him. Luke relates in Acts 27:2 that when the ship set sail from Caesarea "Aristarchus, a Macedonian of Thessalonica, being with us." Luke’s own sterling loyalty to Paul, and his unfailing refusal to leave his friend no matter what vicissitudes or misfortunes may befall, is well known. It is not so easily realised that Aristarchus also displayed much the same characteristics, and was with Paul almost as long as was Luke.
With Luke, he shared Paul’s two years imprisonment at Rome. This we know from Paul’s letter to the Colossians (ch.4:10) in which he says "Aristarchus my fellowprisoner saluteth you, and Marcus" (Mark). The latter, it is known, made his own way to Rome and spent some time there with the Apostle during those two years. The reference to "fellow‑prisoner" probably only means that Aristarchus had voluntarily elected to stay with the Apostle while he was detained in Rome. A round dozen or more, from Greece and Asia, came and went at various times during that two years, but Aristarchus and Luke were there all the time. Another greeting from both these stalwarts appears in the epistle to Philemon (v.24) at about the same time and that is the last that is definitely stated of Aristarchus. Still with the Apostle, still waiting to know what the Roman authorities were going to do, still preaching the gospel in Rome.
When, at the end of the two years, Paul was acquitted and free to go where he liked, what happened to Aristarchus? Of those who visited Rome during this period the subsequent movements of all can be accounted for except those of Aristarchus. All others, except Luke, left Rome for various Greek and Asian churches. Luke accompanied Paul wherever he went during the ensuing five or six years of which nothing is recorded and was with him when we are able to pick up the thread again. The logical inference is that Aristarchus stayed with him also. If in fact Paul did occupy that silent six years with a missionary tour through Spain, Gaul (France) and Britain, which is the most likely hypothesis, then these two were his companions in that tour. When Paul comes again into sight he is journeying through Dalmatia and lllyricum (former Yugoslavia) and Greece, thence across Macedonia to Berea, voyaging to Crete and back to Nicopolis on the west coast for the winter. (1 Tim.1:3; Titus 3:12) then through Berea, Thessalonica and Philippi to Troas, where he was arrested for the second time. From there he was taken to Rome, but now only Luke was with him. The implication is that Aristarchus was left in one of the Greek communities—probably his old home at Thessalonica—at Paul’s request, to serve the interests of the faith, and that is as far as logical inference can trace him.
He was a constant companion of and fellow‑worker with the Apostle Paul for something like thirteen years, sharing with him the toils and trials of the way, steadfast in his chosen mission of declaring the good tidings of Christ. Luke was the only one who could claim a longer period of companionship with Paul: he joined Paul several years before the other man came on the scene and remained with Paul until the Apostle’s death. There must have been a special friendship between these two; they were both Greeks, they both owed their enlightenment to Paul, they both travelled with him more consistently than any others, more so even than Mark or Timothy, both of whom had other pastoral charges to administer at different times in their careers. His biography, had it been written, would surely have been of absorbing interest to all who realise what a debt is owed to these stalwarts of the middle First Century who, with Paul their acknowledged leader, blazed the trail of Christianity for us to follow. As it is, all we can do is raise our hands in salute to that hardy soul whom we only know in Luke’s words as "Aristarchus, a Macedonian, of Thessalonica."