Inasmuch as many have undertaken to compile a narrative of the things that have been accomplished among us, just as those who from the beginning were eyewitnesses and ministers of the word have delivered them to us, it seemed good to me also, having followed all things closely for some time past, to write an orderly account for you, most excellent Theophilus, that you may have certainty concerning the things you have been taught. [Luke 1:1-4 ESV]
Luke wrote over a quarter of the New Testament, was a sometimes companion of Paul from his second missionary journey to his imprisonment in Rome. While Paul was imprisoned in Caesarea for two years before appealing to Caesar Luke and had many opportunities to interview eyewitnesses to Jesus’ life, death, and resurrection.
Though his relationship with Paul is understated he accompanied Paul on many of his journeys beginning from his trip from Troas to Macedonia. This verse changes from the third person to the first person telling us when Luke joined Paul’s company. “And when Paul had seen the vision, immediately we sought to go on into Macedonia, concluding that God had called us to preach the gospel to them” [Acts 16:10 ESV]. After appealing to Caesar Luke accompanies Paul, who is in change, to Rome. “And when it was decided that we should sail for Italy” [Acts 27:1 ESV]. “And when we came into Rome, Paul was allowed to stay by himself, with the soldier who guarded him” [Acts 28:16 ESV].
Paul mentions Luke three times in his letters (Colossians 4:14; 2 Timothy 4:11; and Philemon 24) but he never mentions his own name. When Luke wrote to Theophilus it was with the express intent to tell him the truth. He was not an eyewitness to the events recorded but painstakingly searched for and interviewed those who were. While Paul was imprisoned in Caesarea Luke had ample opportunity to travel throughout the country and collect his information. He interviewed eyewitnesses to Jesus’ life, death and resurrection.
In the first book, O Theophilus, I have dealt with all that Jesus began to do and teach, until the day when he was taken up, after he had given commands through the Holy Spirit to the apostles whom he had chosen. He presented himself alive to them after his suffering by many proofs, appearing to them during forty days and speaking about the kingdom of God. [Acts 1:1-3 ESV]
Luke obviously spoke to many people collecting stories about Jesus. While we don’t know much about the man himself we can see the quality of his work, of his research and writing abilities. He never claims to be an eyewitness but does claim to have spoken with eyewitnesses. He was a careful researcher and used the best Greek to express himself. He used medical terms liberally, words which would not have been used by a poor Jew of Galilee or Judah. He did not use slang nor quote from others. What he wrote was in his own style. His intent was to verify and validate the stories told Theophilus for his assurance.
While there are many stories in the Gospel of Luke found in Mark and Matthew and even John, there are also many unique to his gospel. Over and over he gives points of historical significance from a perspective of the Greek not the Jew. Many have tried to debunk Luke as the author suggesting His historical references are wrong. Over and again, as more evidence is discovered and collected, his historical references have been shown accurate.
While not a biography of Jesus the Gospel of Luke does have a unique vision of the man. He collected and presented evidence which shows Jesus is who He says He is.
“O foolish ones, and slow of heart to believe all that the prophets have spoken! Was it not necessary that the Christ should suffer these things and enter into his glory.” Beginning with Moses and all the Prophets, he interpreted to them in all the Scriptures the things concerning himself. [Luke 24:25-27 ESV]
Add to this the evidence of the growth of the Church in the Acts of the Apostles and you find a complete picture of Christ changing people and making them His own.
Luke did not do this work for himself nor just for Theophilus. He was driven needing to know the truth and to test that truth about the one called Jesus. He did not falter or plagiarize or make up a fantasy. He hungered and thirsted for righteousness by demanding of himself a knowledge of the evidence of what he believed. He trusted the object of his faith, willing to associate and even care for Paul while traveling to hostile regions and sitting in jails and prisons. He obeyed the commands of his God even when it meant putting himself at risk.
He needed to know.