Both Matthew and Luke speak about the birth and infancy of Jesus, but share little concerning other details of His early life. Why not?
Why doesn't the Bible say much about Jesus' childhood?
First, it can be argued that much is shared about the childhood of Jesus. We are told the accounts before His birth, including an angel predicting His virgin birth to Mary and to Joseph on separate occasions. His birth is recorded in two Gospels. He would have been circumcised on the eighth day following Jewish custom. About 40 days after His birth, his parents traveled to Jerusalem for rites related to purification (Luke 2:23) and had special visits with Simeon and Anna. Wise men visited at some time after His birth at a time when Jesus was in a "house" in Bethlehem (It is unclear if this occurred before or after the Jerusalem visit.). Joseph was then warned in a dream to take the family to Egypt to escape Herod's plan to kill Jesus. After Herod's death, the family moved back to their hometown of Nazareth (sometime during the reign of Archelaus between 4 B.C. to 6 A.D.). At the age of twelve, Jesus traveled with His family to the temple and stayed behind for three days discussing the Law with the religious teachers. Luke 2:52 summarizes His early life by stating, "Jesus increased in wisdom and in stature and in favor with God and man." The Bible is then silent on the life of Jesus after the age of twelve in Nazareth to about the age of thirty or His early thirties when He began His public ministry.
The emphasis of all four Gospels is on Jesus as the Messiah. The only material shared from the early life of Jesus was what was needed to help fulfill this purpose. The Gospels were not strict biographies, but rather summaries of the earliest teachings about Jesus from His followers and those associated with them.
Later legendary accounts about the "lost years" of Jesus must be dismissed as unhistorical accounts. Jesus and His family likely returned to Nazareth when He was still a toddler, meaning the accounts from the Gnostic Gospel of Thomas and similar writings are at odds with the known historical details.
It must be noted that God's Word never intended to reveal every detail, including the details concerning the early life of Jesus. Deuteronomy 29:29 teaches, "The secret things belong to the LORD our God, but the things that are revealed belong to us and to our children forever, that we may do all the words of this law." The Lord has only chosen to reveal some of the information about Christ's life for us today. What has been revealed is important to study and apply. What is unrevealed is unrevealed for reasons God has sought not to communicate at this time.
We are blessed to have four Gospels complete with the main aspects of Christ's early life, as well as the crucial teaching from Jesus and the information concerning His death and resurrection.
Did Jesus go to India before starting His public ministry?
Was Jesus a Jew?
Did Jesus have brothers and sisters (siblings)?
Where was Joseph during Jesus' adulthood?
What were the key events in the life of Jesus?
Truth about Jesus Christ