Luke is the person who wrote the Gospel of Luke and the Acts of the Apostles, and his profession was a physician.
Since the Gospel of Luke and the Acts of the Apostles were written in Greek, he appears to have been highly educated. In Acts 1:19, it mentions the Aramaic language of the Jews, referring to "their own language."
Acts 1:9After he said this, as they were watching, he was lifted up, and a cloud took him out of their sight.
This suggests that Luke's native language was likely Greek, not Aramaic.
In several epistles written by Paul, Luke is shown to be a very faithful co-worker.
2 Tim 4:11Only Luke is with me. Get Mark and bring him with you, because he is helpful to me in my ministry.
Luke, in particular, tends to cover up the mistakes of the disciples who were with Jesus, whereas other Gospels explicitly describe them.
Mark 8:32He spoke plainly about this, and Peter took him aside and began to rebuke him.Mark 8:33But when Jesus turned and looked at his disciples, he rebuked Peter. “Get behind me, Satan!” he said. “You do not have in mind the concerns of God, but merely human concerns.”
This scene from Mark's Gospel is omitted in Luke's Gospel.
Furthermore, regarding the episode where Peter would deny Jesus three times the day before Jesus was arrested, Luke adds the detail that Jesus prayed for him.
Luke 22:31“Simon, Simon, Satan has asked to sift all of you as wheat.Luke 22:32But I have prayed for you, Simon, that your faith may not fail. And when you have turned back, strengthen your brothers.”Luke 22:33But he replied, “Lord, I am ready to go with you to prison and to death.”Luke 22:34Jesus answered, “I tell you, Peter, before the rooster crows today, you will deny three times that you know me.”Luke 22:35Then Jesus asked them, “When I sent you without purse, bag or sandals, did you lack anything?” “Nothing,” they answered.Luke 22:36He said to them, “But now if you have a purse, take it, and also a bag; and if you don’t have a sword, sell your cloak and buy one.Luke 22:37It is written: ‘And he was numbered with the transgressors’; and I tell you that this must be fulfilled in me. Yes, what is written about me is reaching its fulfillment.”