Let us consider Luke 2:41-52 first.
Amazingly enough, Luke 2:41-52 provides us with the only story in the four canonical gospels that tells us anything about what Jesus was like after his birth and before the age of about 30. This reminds us that none of the gospel writers were trying to write exhaustive biographies of Jesus that chronicled all of the significant events in his life from womb to tomb. They had decided to present only certain vignettes that would reveal to us something about Jesus' character.
The very first thing we learn from this Lukan story is how devout Jesus' parents were. Every year, they would make the long pilgrimage on foot from Nazareth to Jerusalem for the feast of Passover, the spring celebration of the Jews' deliverance from Egypt. We are then told about a particular visit to Jerusalem when Jesus was 12. That would possibly place the visit just after the beginning of the administration of Judea as a Roman province, which is to say, just after the demise of Archelaus, the last son of Herod the Great to rule Judea during Jesus' lifetime. Luke is not really interested in telling us what Jesus and his family did during the festal week in Jerusalem but rather skips directly to the point when the family was to return to Nazareth.
Joseph and Mary and other kin began the trek back to Galilee, assuming that Jesus was among the pilgrims going home. But, a day into their journey, they discovered he was not among them.
Jesus, however, had remained behind in Jerusalem. After they realized this, the holy family returned to Jerusalem and spent three entire days searching for him. We can only imagine how frantic they were by the end of this time. They finally found him in the Temple courts listening to the teachers there and asking them questions. The text also says that he was doing more than asking; he was answering questions and astounding all those listening with his knowledge and understanding. It was not just the Jerusalemites who were astounded. Verse 48 says that even his parents were astonished. It is clear from this story that even Mary and Joseph had not fully grasped who Jesus was or what his mission in life would be.
The words of Mary that follow in verse 48 must be interpreted in light of this fact. She says in a somewhat accusatorial tone: "Son why have you treated us like this? Your father and I have been anxiously searching for you."
Jesus' response is equally surprising. "Why were you searching for me? Didn't you know I had to be in my Father's house?" But they clearly did not know or understand this, or they would not have been astonished at finding him there; never mind the fact that this was hardly the first place they looked when they returned to Jerusalem. Notice also how Mary spoke of Joseph as Jesus' father, but Jesus replied by speaking of God as his true Father. This is important and provides a glimpse of one of the major emphases in Jesus' own teaching later in life--the fatherhood of God (see, for example, the Lord's Prayer in Matthew 6:9). At 12, Jesus already had a sense of his unique identity and his calling to be doing ministry. Notice how strongly Jesus has put the matter--he must be in his Father's house and doing his Father's business.
Nevertheless, he has put his parents on notice that he must do God's will in his life.We are told that Mary stored away in her mind what Jesus had said and done on this day and ruminated on its meaning--the trait of a good disciple who needs further understanding. The story closes with an interesting remark about Jesus' growing in wisdom and stature and in favor with God and human beings. This reminds us that Jesus, while being the unique Son of the Father, was also truly and fully human. He grew up and gained knowledge and wisdom over the course of time.
This story introduces the reader to Jesus in the Lukan scheme of things and makes clear from the outset the religious focus and nature of his adult life. Where had he chosen to make his first public appearance? At the very heart of Judaism, in the Temple in which God's presence was thought especially to dwell. This appearance sets the reader on notice that someone very special has arrived on the scene, someone whose every appearance would prompt an array of responses, from surprise, astonishment, and dismay, to joy.