It is very helpful that Luke introduces his Gospel by giving the reasons why he decided to write it. He mentions that many others have attempted to do the same thing. There are many apocryphal Gospels-for example, Gospels attributed to Philip, Mary Magdalene, Thomas, Philip, even Judas Iscariot! Luke's assertion is that his has been written after a lot of research and with the intention of finding and sticking to the truth.
He writes to young Christians: 'Theophilius' could be taken as being written to one person, but it is more likely to be read generally, 'Theophilius' meaning 'Reader' or 'friend of God' in the Greek. So, it is to a Greek audience he writes for and thus his Gospel does not concerns itself as much with fulfillment of Old Testament prophecy as Matthew's does.
I like Luke. He seems to have been a faithful companion to the Apostle Paul when he was chronically ill and he was a defender of the poor, sick and marginalised. His Gospel is full of recordings of how Jesus supported and blessed those people and stood up against people of power who ruled unjustly.
I've spoken recently about those who were insignificant in the world's eyes, who were chosen by God to be central to the birth of His Son. We will study some of them in the days to come.