"Honour thy father and thy mother that thy days may be long upon the land which the LORD thy God giveth thee." Exodus 20:12
The command is not limited only to the "young" or "dependent" child, but also applies to an adult child. Though an adult is not required to "obey" or "submit" to the rules and commands of his parents, an important element of honor is respecting and caring for them.
It is a Biblical promise that the child who honors his/her parents will live a long (complete) life.
Observance of this commandment is critical. It is through this command that a child begins to develop faith, obeying without fully understanding why. It is the most fundamental lesson we must learn as it conditions us in relating to other authorities throughout our lives (employer, minister, government, teacher, etc.). Most importantly, if a child can learn to trust his parents without always understanding, he begins building the foundations for trusting God.
By honoring one's parents, we also directly submit to God through His "chain of command". The rewards life holds for such a person are unimaginable!
Jesus Obeys His Parents
Luke 2:41-51
Now his parents went to Jerusalem every year at the feast of the passover.
And when he was twelve years old, they went up to Jerusalem after the custom of the feast. And when they had fulfilled the days, as they returned, the child Jesus tarried behind in Jerusalem; and Joseph and his mother knew not of it . But they, supposing him to have been in the company, went a day's journey; and they sought him among their kinsfolk and acquaintance. And when they found him not, they turned back again to Jerusalem, seeking him. And it came to pass, that after three days they found him in the temple, sitting in the midst of the doctors, both hearing them, and asking them questions. And all that heard him were astonished at his understanding and answers. And when they saw him, they were amazed: and his mother said unto him, Son, why hast thou thus dealt with us? behold, thy father and I have sought thee sorrowing. And he said unto them, How is it that ye sought me? wist ye not that I must be about my Father's business? And they understood not the saying which he spake unto them. And he went down with them, and came to Nazareth, and was subject unto them: but his mother kept all these sayings in her heart. And Jesus increased in wisdom and stature, and in favour with God and man.