Why is Jesus at the center of everything If you look through the Bible we know that Jesus is at the center of everything both in the old and new testament. 

I have some clues like him being beloved or as a reward of what he suffered. 


  John 3:35 
  
  The Father loveth the Son, and hath given all things into
  his hand


and


  Philippians 2:8-9
  
  8 And being found in fashion as a man, he humbled himself, and became
  obedient unto death, even the death of the cross.
  
  9 Wherefore God also hath highly exalted him, and given him a name
  which is above every name


I feel my clues are not concrete or complete so I would like a broader view or complements.
Reason 1


According to reformed theology, the Bible is about the Glory of God.
Jesus is God.
Thus, the Bible is about Jesus.


More concretely, some would go so far as to state that the Elect is the father's gift to the Son (I'm not sure if this can be scripturally verified). That would be further reason for the Bible focusing on Christ.

Reason 2

Without Jesus, these would be no forgiving of sins. Without the forgiving sins, the Bible would be a very different book.