He is certainly man -- he prayed, he suffered, he was tempted. We also know for certain that He is God in a complete sense; He is true God and true man.
(John 1:1-14):
1 In the beginning was the Word, and the Word was with God, and the Word was God.
2 The same was in the beginning with God.
3 All things were made by him: and without him was made nothing that was made.
4 In him was life, and the life was the light of men.
5 And the light shineth in darkness, and the darkness did not comprehend it.
6 There was a man sent from God, whose name was John.
7 This man came for a witness, to give testimony of the light, that all men might believe through him.
8 He was not the light, but was to give testimony of the light.
9 That was the true light, which enlighteneth every man that cometh into this world.
10 He was in the world, and the world was made by him, and the world knew him not.
11 He came unto his own, and his own received him not.
12 But as many as received him, he gave them power to be made the sons of God, to them that believe in his name.
13 Who are born, not of blood, nor of the will of the flesh, nor of the will of man, but of God.
14 And the Word was made flesh, and dwelt among us, (and we saw his glory, the glory as it were of the only begotten of the Father,) full of grace and truth.
(John 10:30):
30 I and the Father are one.
(John 8:58):
58 Jesus said to them: Amen, amen I say to you, before Abraham was made, I am.
(Revelation 21:6):
6 And he said to me: It is done. I am Alpha and Omega; the beginning and the end. To him that thirsteth, I will give of the fountain of the water of life, freely.
(Revelation 22:6-16):
6 And he said to me: These words are most faithful and true. And the Lord God of the spirits of the prophets sent his angel to shew his servants the things which must be done shortly.
7 And, Behold I come quickly. Blessed is he that keepeth the words of the prophecy of this book.
8 And I, John, who have heard and seen these things. And after I had heard and seen, I fell down to adore before the feet of the angel, who shewed me these things.
9 And he said to me: See thou do it not: for I am thy fellow servant, and of thy brethren the prophets, and of them that keep the words of the prophecy of this book. Adore God.
10 And he saith to me: Seal not the words of the prophecy of this book: for the time is at hand.
11 He that hurteth, let him hurt still: and he that is filthy, let him be filthy still: and he that is just, let him be justified still: and he that is holy, let him be sanctified still.
12 Behold, I come quickly; and my reward is with me, to render to every man according to his works.
13 I am Alpha and Omega, the first and the last, the beginning and the end.
14 Blessed are they that wash their robes in the blood of the Lamb: that they may have a right to the tree of life, and may enter in by the gates into the city.
15 Without are dogs, and sorcerers, and unchaste, and murderers, and servers of idols, and every one that loveth and maketh a lie.
16 I Jesus have sent my angel, to testify to you these things in the churches. I am the root and stock of David, the bright and morning star.