1. Luke is mentioned three times in the Bible

Saint Luke is mentioned in three passages of Scripture:

• In Colossians 4:14, Saint Paul writes: “Receive the greetings of Luke, our beloved physician, and of Demas.”
• In 2 Timothy 4:11, Paul writes: “Only Luke is with me. Take Marcos with you, because he will be very useful to me for the ministry.”
• And in Philemon 23-24, Paul writes: “Epaphras, my fellow captive in Christ Jesus, greets you, and also Mark, Aristarchus, Demas and Luke, my helpers.”

Since Luke is mentioned in three letters, we can infer that he was a frequent companion of Saint Paul. He also participated in his work, since he is known as one of his “collaborators.”

The fact that Saint Paul says, in his last letter, that “Luke is alone with me” suggests that he was a particularly close and faithful companion.

Finally, the reference to Luke as “the beloved physician” indicates that his “daily work” (as opposed to his apostolic efforts) was as a physician.

2. Saint Luke wrote the third Gospel and Acts of the Apostles

Saint Luke is identified by early tradition (2nd century) as the author of the third Gospel and as the author of the book of the Acts of the Apostles.

He may also have had a role in the composition of some of the letters attributed to Saint Paul.

Even if he only wrote the third Gospel and Acts, he still wrote more of the New Testament than any other author! Both texts add up to almost 38 thousand words, or 24% of the entire New Testament.

3. The Gospel of Saint Luke is synoptic

The Gospel of Saint Luke is one of the three “Synoptic Gospels,” meaning that it covers much of the same territory as those of Saint Matthew and Saint Mark.

As a result, if the Gospel of Luke had not been written, there would still be a large part of the story of Jesus that would have been preserved (not only by Matthew and Mark, but also by John). However, there are certain things that only Luke records.

Among them are these passages:

• The birth of John the Baptist is predicted (1:5-25)
• The birth of Jesus is announced (1: 26-38)
• The visitation (1:39-56)
• The birth of John the Baptist (1:57-80)
• The circumcision and presentation of Jesus (2: 21-40)
• The discovery in the temple (2: 41-52)
• The son of the widow of Nain (7: 11-17)
• The Mission of the Seventy (10:01-20)
• The Good Samaritan (10:29-37)
• “Mary has chosen the good part” (10: 38-42)
• The friend at midnight (11:5-8)
• The parable of the rich fool (12: 13-21)
• The parable of the lost coin (15:8-10)
• The parable of the lost son (15: 11-32)
• The Parable of the Wise Steward (16:1-8)
• Lazarus and the rich man (16: 19-31)
• Ten lepers purified (17:11-19)
• The Parable of the Persistent Widow (18:1-8)
• The parable of the Pharisee and the tax collector (18:9-14)
• Dinner with Zacchaeus (19:1-10)
• Who is the greatest? (22:24-32)
• Jesus before Herod Antipas (23:6-12)

If these were not recorded in the Gospel of Luke, no one would know about them, because they are not recorded anywhere else in the New Testament.

4. Saint Luke used written sources and eyewitnesses to write his Gospel

 At the beginning of his Gospel, Luke writes:

“Some people have endeavored to put together a narrative of the events that have occurred among us, as they have been transmitted to us by those who were the first witnesses and who later became servants of the Word. After having carefully investigated everything from the beginning, it also seemed good to me to write an organized story for you, illustrious Theophilus.”

Luke's reference to the Gospel accounts of events that preceded him, and his reference to having “carefully investigated everything,” seems to indicate that he used written sources for some of his information.

Given the similarities Luke has with Matthew and Mark (the other two synoptic gospels), it is likely that he used one or both.

He also says that he obtained information from “first witnesses and who later became servants of the Word.”

One of the witnesses he probably interviewed was the Virgin Mary herself. Luke records the material in the infancy narrative in a way that implies that Mary was the source of much or all (Luke 2:19, 51).

One of the servants of the Word that he probably used as a source was Saint Paul. One way to demonstrate this is that the words of institution of the Eucharist in the Gospel of Luke (Luke 22: 19-20) are very similar to the formula used by Saint Paul (1 Corinthians 11: 24-25). It is less similar to the formula used in Matthew and Mark (Matthew 26:26-28, Mark 14:22-24). 

It is likely that he used the formula used by Saint Paul because he frequently heard him celebrate Mass and this was the version most familiar to him.

One individual who was both an eyewitness and a minister of the word, whom Luke probably interviewed, is Saint Peter. We have good reason to think that this apostle was one of the sources of the Acts. If Luke interviewed him for that, he probably did it for his Gospel as well.

5. Acts of the Apostles covers the earliest history of the Church after the Ascension

The Acts of the Apostles covers a period extending from 33 AD to 60 AD

Without this book, we could deduce little about this period from the New Testament letters. For example, there were churches in the cities to which letters about some events in Paul's life were sent.

Luke did us a great service by not stopping with the end of his Gospel and continuing to record the history of the early Church beyond the death and resurrection of Jesus.

6. Acts of the Apostles was also nourished by written sources and witnesses

As with the Gospel, Luke probably obtained his information for the Acts of the Apostles both from written sources and from interviews with eyewitnesses and servants of the word.

Luke also witnessed many of the events written about. This is indicated by what are known as the “we” passages in Acts, places where the author talks about what we “did” and where we “went,” indicating that he was present.

There are four such passages:

• Acts 16:10-17
• Acts 20:5–15
• Acts 21:1–18
• Acts 27:1–28

One written source that Luke probably used is a travel journal he kept of Paul's travels. Luke himself may have been the author of this diary, although it may have been kept by someone else in the Pauline circle.

The “we” passages indicate that he had frequent access to Paul, and we know that he also had access to Peter and Philip the Evangelist:

• He would have had access to Peter during the two years that Paul was under house arrest in Rome (Acts 28:30), where Peter was also ministering.
• He would have access to Philip the Evangelist during the two years that Paul was detained in Caesarea Maritima (Acts 23:33, 24:27), where Philip lived (Acts 21:8-9).

7. The Gospel of Luke and Acts were written almost at the same time

They were written as complementary pieces and dedicated to the same individual (Theophilius). Therefore, they were probably written at the same time.

Since Acts is suddenly interrupted in AD 60, before Paul has had a chance to appear before Caesar, it is likely that this happened when the book was finished.

Both Luke and Acts were probably written in Rome in 59-60 AD

8. Luke would have helped Paul write one of the letters

Luke is never named as one of Paul's co-authors, but the Apostle frequently used secretaries in the process of writing his letters (see, for example, Rom. 16:22).

These secretaries, known as amanuenses, might be tasked with writing a letter on behalf of another, based on talking points given by the one for whom they were writing.

Particularly when in prison, Paul may have used Luke in this capacity, and some have noted similarities in the style of Luke-Acts and some of the letters attributed to Paul, particularly the pastoral letters (1-2 Timothy, Titus).

The fact that, in 2 Timothy, Paul says that “Luke alone is with me” (2 Timothy 4:11) may indicate that Luke was the scribe Paul used to write this letter.

Although the Epistle to the Hebrews is not attributed to Paul, many have noted the similarity of the style of this book with the Gospel of Luke and Acts, so the evangelist has been proposed as a possible author.

9. Luke would have been a Gentile and not a Jew

Although some have argued that he was Jewish, Luke is generally thought to have been a Gentile. One reason is that, in Colossians, he is mentioned separately from those “of the circumcision”:

“Aristarchus, my fellow prisoner, and Mark, Barnabas' cousin, greet you, about whom you have already received instructions. If he goes there, give him a good welcome. Jesus, nicknamed Justus, also greets them. They are the only ones of the Jewish race who are working with me for the Kingdom of God, and who have been a comfort to me. Receive greetings from your compatriot Epaphras; He is a good servant of Christ Jesus who is always praying fervently for you so that you may be perfect and produce all the fruits that God desires. I can assure you that he has missed them very much, as well as those from Laodicea and Hierapolis. Receive greetings from Lucas, our dear doctor, and from Demas.” [Colossians 4:10-14]

10. Church Father Saint Jerome wrote about Luke

What the Church Fathers wrote cannot be reviewed in detail, but this is part of what Saint Jerome wrote about Luke in his text Lives of illustrious men:

“Luke, a physician from Antioch, as his writings indicate, was not inexperienced in the Greek language.

Follower of the apostle Paul, and companion of all his travels, he wrote a Gospel, about which Paul himself says: 'We sent with him a brother whose praise in the gospel is among all the churches'; and to the Colossians: 'Luke, the beloved physician, greets you'; and Timothy: 'Only Luke is with me.'

He also wrote another excellent volume to which he prefixed the title of the Acts of the Apostles, a history that extends until the second year of Paul's stay in Rome, that is, until the fourth year of Nero, from which we learn that The book was composed in that same city…

He was buried in Constantinople, a city to which, in the twentieth year of Constantius, his bones were transferred together with the remains of the apostle Andrew.”

Translated and adapted by Diego López Marina. Originally published in National Catholic Register.