King James Version
And he came and dwelt in a city called Nazareth: that it might be fulfilled which was spoken by the prophets, He shall be called a Nazarene.
Joseph Smith, the only Seer of the last days, was authorized to add significantly to the end of this verse.
JST
...He shall be called a Nazarene. And it came to pass that Jesus grew up with his brethren, and waxed strong, and waited upon the Lord for his ministry to come. And he served under his father, and he spake not as other men, neither could he be taught; for he needed not that any many should teach him. And after many years the hour of his ministry drew nigh.
This is not mere corrections of spelling or grammar. This is adding 8 significant phrases to the canon of scripture. If Joseph were a pretender to the prophetic, then he would have been cunning enough to keep his corrections simple. This one verse thunders with the audacious, yet true claim, that Joseph Smith is a prophet of GOD.
1. CHRIST was humble enough to serve under his stepfather Joseph. I, myself am a stepfather, and my 4 children do not always serve humbly under even their own "real" mother. The greatest being to touch this earth, had no problem following directions from his temporary father. Undoubtedly the MOST HIGH GOD (EL, EL ELYON, or ELOHIM) picked the best man of the day to raise his SON.
2. CHRIST came to this fallen sphere knowing more than all of its inhabitants past, present, and future put together. No one could teach him. His language was different because he always spoke the truth.
3. Even GOD the SON had to wait "many years" before he could began his work saving souls, healing the sick, raising the dead, preaching the great news of the gospel, baptizing with water and spirit, and ultimately working out the infinite atonement. JESUS had to wait until the timing was perfect. Men always tend to rush in before being called by Heaven, and then are forced to use coercion to keep people in line.