The question is often raised about the “lost years of Jesus.” Why are we given the infancy story and then nothing until he’s an adult? The question really is based on a misunderstanding of the infancy narratives. They are not the first chapter, chapter one of the life of Jesus, with, as it were, chapters two and three (Jesus grows up, Jesus goes to college) missing, and then the adult life of Jesus. The infancy narratives are overtures, not first acts but overtures. The function of an overture is to give you a musical medley, a thematic overview of what is to come. Usually overtures are written after the play has been completed. The infancy stories, therefore, must be taken as overtures, not first acts or first chapters.
Each Gospel has an overture. Two of them (Matthew and Luke) have infancy stories as overtures. There are no lost sections in those two Gospels. The first section is an overture, and then you go straight into the story.
When you read those two stories in Matthew 1–2 and Luke 1–2, the first thing that should strike you is that they are totally different. Even if we can get them organized and get the Magi and the shepherds around the crib so we don’t notice the problem, they’re totally different. But of course they should be totally different if they are overtures to different Gospels.