What does Luke 2:52 mean?

This is another reminder from Luke that Jesus' humanity was legitimate—it was complete (Luke 2:19). Like any other human being, He matured both physically and mentally. That included growing in physical ways, as well as learning and increasing His earthly knowledge. Jesus' experience of life on earth was the same as for any other man, other than His complete lack of sin (Hebrews 4:15. 1 Peter 2:22). He was not born with an instant ability to walk, speak, or build furniture. He learned as children learn. He grew as children grow.

Scripture provides very few details about Jesus' upbringing or His childhood. This is likely for the same reason the Bible gives no specifics about His appearance. As fallible people, we tend to obsess over irrelevant details. One can only imagine what would happen if parents were comparing their child's first steps, first words, or eye color to that of the Savior. Not only are those facts meaningless, spiritually speaking (Isaiah 53:2), but they would also have made God's Word cumbersome (John 21:25).

In keeping with that efficiency, the next passage of Luke's writing will leap ahead about eighteen years. This will move the story to the public ministry of John the Baptist. He will preach to great effect, preparing people for the official revealing of the Messiah (Luke 3:1–4).