Jesus was fully God and fully man.  
He was God Himself who took on the form of a man.
That man had to be fully human in order to be tempted in all ways as a human.
And fully God to be able to substitute for all humans.
The God inside the flesh of Jesus is THE one God of Abraham, who is eternal.
The flesh wrapped around God as the visible Jesus was born and had a beginning.
In that flesh Jesus laid aside some of his prerogatives as God - including not knowing a few things.  If He had known all things he could not have been fully human, and tempted as we are.

> In your relationships with one another, have the same mindset as Christ Jesus: Who, being in very nature God, did not consider equality with God something to be used to his own advantage; rather, he made himself nothing by taking the very nature of a servant, being made in human likeness. And being found in appearance as a man, he humbled himself by becoming obedient to death—even death on a cross!  - 2 Phillippians 2:5-8

> Since the children have flesh and blood, he too shared in their humanity so that by his death he might destroy him who holds the power of death-- that is, the devil-- and free those who all their lives were held in slavery by their fear of death. For surely it is not angels he helps, but Abraham’s descendants. For this reason he had to be made like his brothers in every way, in order that he might become a merciful and faithful high priest in service to God, and that he might make atonement for the sins of the people. Because he himself suffered when he was tempted, he is able to help those who are being tempted. -  Hebrews 2:14-18 

> No one has ever seen God, but the one and only Son, who is Himself God and is at the Father’s side, has made Him known.   -- John 1:18

> Behold, I am coming quickly, and My reward is with Me, to give to each person according to what he has done. I am the Alpha and the Omega, the First and the Last, the Beginning and the End.” - Revelation 22:13

> “In Christ all the fullness of the Deity lives in bodily form” (Colossians 2:9).