Disciple not believer

Why John wrote John Gospel

But these are written that you may believe that Jesus is the Messiah, the Son of God, and that by believing you may have life in his name.
John 20:31 NIV
http://bible.com/111/jhn.20.31.NIV

Prior John the Matthew,  Like etc already exist.  Hence John was writhing some time not exist in these books.

“My food,” said Jesus, “is to do the will of him who sent me and to finish his work.
John 4:34 NIV
http://bible.com/111/jhn.4.34.NIV

The characterof son coming from the Father

Jesus gave them this answer: “Very truly I tell you, the Son can do nothing by himself; he can do only what he sees his Father doing, because whatever the Father does the Son also does.
John 5:19 NIV
http://bible.com/111/jhn.5.19.NIV

Eternal food

Do not work for food that spoils, but for food that endures to eternal life, which the Son of Man will give you. For on him God the Father has placed his seal of approval.”
John 6:27 NIV
http://bible.com/111/jhn.6.27.NIV

Jacob and Esau
God hated Esau because he sold his birth right for a temporary meal.

The world and its desires pass away, but whoever does the will of God lives forever.
1 John 2:17 NIV
http://bible.com/111/1jn.2.17.NIV

Don't love the world. Don't sell your externality.

To give God an empty sheet of paper and whatever God wrote I do.