That Luke was inseparable from Paul and his fellow-laborer in the Gospel, he himself clearly evinces, not as a matter of boasting, but as bound to do so by the truth itself. For when Barnabas and John Mark, had parted company from Paul and sailed to Cyprus, Luke writes: “We came to Troas” (Acts 16,8.11)… Then he carefully indicates all the rest of their journey as far as Philippi, and how they delivered their first address… And all the remaining details of his journey with Paul he recounts with all possible diligence… As Luke was present at all these occurrences, he carefully noted them down in writing, so that he cannot be convicted of falsehood or boastfulness, because all these details were well known… That Luke was not merely a follower, but also a fellow-laborer of the apostles, and especially of Paul, Paul himself declared too in his Epistles, saying: “Demas has forsaken me and has left for Thessalonica; Crescens to Galatia, Titus to Dalmatia. Only Luke is with me” (2Tim 4,11). From this Paul shows that Luke was always attached to and inseparable from him. And again, in the Letter to the Colossians he says: “Luke, the beloved physician, greets you” (Col 4,14)… There are also many other particulars to be found in the Gospel that are mentioned by Luke alone… It may be, indeed, that it was of set purpose that God set forth very many Gospel truths, through Luke’s instrumentality alone…, in order that all might follow his subsequent testimony treating of the acts and doctrine of the apostles, and that thus holding the unadulterated rule of truth, they might be saved. Luke’s testimony, therefore, is true and the doctrine of the apostles is open and steadfast, holding nothing in reserve… Theirs are the voice of the Church from which the Church takes its origin.
Roman Extraordinary (Tridentine) Daily Readings – rosary,team