Luke was the only Gentile author to be included in the New Testament. This is significant because until the advent of Jesus, the God of Abraham, Isaac, and Jacob was the God of the Israel. And although God's universal intent was manifest throughout their history, Israel had glommed on to the exclusivity of their position as God's chosen people.
Luke shows us God is not confined by genealogies or past behaviors. In this way the person of Luke is a reflection of the reality of the gospel. Luke was not a member of the Old Testament covenant community. Yet, God used him to narrate the gospel of Jesus to untold numbers of people up until today, both through his person and his two-part series. Luke was not distracted by his lack of pedigree. In the same way, modern cross-cultural gospel narrators need not despair of their physical or spiritual parentage.