A lot of people-- even some Christian teachers -- say that because the Bible is silent about the life of Jesus from his 13th birthday (bar-mitzvah Luke 2:27) to the beginning of his public ministry at age 30 (Luke 3:23), we know nothing about the life of Jesus during the years in-between. But the Bible isn't completely silent about these years. We see from the Bible that Jesus had been brought up in Nazareth and had been reading and teaching in the synagogues of the surrounding areas his whole life:
And he came to Nazareth, where he had been brought up: and, as his custom was, he went into the synagogue on the sabbath day, and stood up for to read.
And look at the people's reactions to his words of wisdom a few verses later:
And all bare him witness, and wondered at the gracious words which proceeded out of his mouth. And they said, Is not this Joseph's son?
In other words, they knew him because he had been raised up there in Nazareth, and in another place in the Bible, we see that the crowd knew him so well that they knew his natural siblings by name:
54. And when he was come into his own country, he taught them in their synagogue, insomuch that they were astonished, and said, Whence hath this man this wisdom, and these mighty works?
55. Is not this the carpenter's son? is not his mother called Mary? and his brethren, James, and Joses, and Simon, and Judas?
56. And his sisters, are they not all with us? Whence then hath this man all these things?
57. And they were offended in him. But Jesus said unto them, A prophet is not without honour, save in his own country, and in his own house.
58. And he did not many mighty works there because of their unbelief.
In other words, Jesus had spent the years of his life between the ages of 13 and 30 in Nazareth and the surrounding cities, studying and teaching in the synagogues.
Why is this important? Because there are a lot of documentaries going around now claiming that Jesus was just another variation of the same old pagan myth of a savior for mankind. One of the aspects of Jesus' history they use as a "similarity" is that of the seeming gap between the ages of 13 and 30. They say Osiris, Mithra, Bacchus, Dionysus, etc, etc all share the same gap. But because we can know from the Bible what Jesus was doing during this time, we can know that the similarities with these other pagan gods were simply made up by modern atheists relying on deception to discredit Jesus. For such an example, go read the article 'Jesus was NOT a pagan copycat!" and watch the clip 'Zeitgeist' at the beginning of it. Busted! While you're there, read the entirety of that article to see how the rest of the clip falls apart too.