12 Then spake Jesus again unto them, saying, I am the light of the world: he that followeth me shall not walk in darkness, but shall have the light of life.

[I am the light of the world The source from which all intellectual light and spiritual understanding proceed; without me all is darkness, misery and death. The Divine Being was described by the rabbins as, The light of the world. So in the Bamidbar Rabba; "The Israelites said to God, O lord of the universe, thou commandest us to light lamps to thee, yet thou art THE LIGHT OF THE WORLD: and with thee the light dwelleth." Our Lord here assumes the well known character of the Supreme Being, and with this we find the Jews were greatly offended.

[Shall not walk in darkness] He shall be saved from ignorance, infidelity and sin. If he follow me, become my disciple, and believe on my name, he shall have my Spirit to bear witness with his, that he is a child of God.

[The light of life] Such a light as brings and supports life. As the sun, the fountain of light, is also the fountain of life, so the Sun of righteousness, (Malachi 4:2) shall provide healing and renewal.

13 The Pharisees therefore said unto him, Thou bearest record of thyself; thy record is not true.

[Thou bearest record of thyself] As if they had said, "Do you imagine that we will take your word only on such an important matter?" Had these people been following the teaching and miracles of Christ they would know that his claim was supported by irrefutable testimony.

14 Jesus answered and said unto them, Though I bear record of myself, yet my record is true: for I know whence I came, and whither I go; but ye cannot tell whence I come, and whither I go.

[I know whence I came] I come from God and am going to God and can neither do nor say anything but that which leads to and glorifies him.

15 Ye judge after the flesh; I judge no man.
16 And yet if I judge, my judgment is true: for I am not alone, but I and the Father that sent me.
17 It is also written in your law, that the testimony of two men is true.
18 I am one that bear witness of myself, and the Father that sent me beareth witness of me.

Because I appear in the form of man, judging from appearance, you think that I am but a mere man. Pay attention to my teaching and miracles and you shall see then that nothing less than infinite wisdom and unlimited power could teach and do what I have taught and performed. Our Lord speaks here in exactly the character of an ambassador. Such a person does not bring a second person with him to vouch his truth; his credentials from his king confirm his character; he represents the king's person. The miracles which Jesus performed were proof from heaven that he was the promised Messiah: these were the great seal of all his claims.

19 Then said they unto him, Where is thy Father? Jesus answered, Ye neither know me, nor my Father: if ye had known me, ye should have known my Father also.

[Ye neither know me, nor my Father] You know neither the Messiah, nor the God that sent him.

[If ye had known me] If you had received my teaching, you would have gained an acquaintance with the nature and attributes of God which could be acquired no other way. This is a true saying, No man hath seen God at any time; the only begotten Son, who is in the bosom of the Father, he hath declared him. (John 1:18). The nature and perfection of our God can never be properly known but in the light of the Gospel of Jesus Christ.

20 These words spake Jesus in the treasury, as he taught in the temple: and no man laid hands on him; for his hour was not yet come.

[The treasury] Lightfoot observes, from the rabbins, that the treasury was in what was called the court of the women. There were thirteen chests in it, the thirteenth where women only were permitted to put their offerings. Probably the other twelve were in reference to the twelve tribes. With many people, including women, coming and going it was a place where Jesus could teach a wide audience.

[His hour was not yet come] The time had not arrived, in which he had determined to give himself into the hands of his crucifiers.

21 Then said Jesus again unto them, I go my way, and ye shall seek me, and shall die in your sins: whither I go, ye cannot come.

[Then said Jesus again unto them] He had said the same things to them before. See John 7:34.

[Ye shall seek me] When your calamities come upon you ye shall seek in vain for the help of the Messiah, whom ye now reject and shall shortly crucify.

22 Then said the Jews, Will he kill himself? because he saith, Whither I go, ye cannot come.

[Will he kill himself] They now understood that he spoke concerning his death; but before, (John 7:35),. they thought he spoke of going to some of the Grecian provinces, to preach to the dispersed Jews.

23 And he said unto them, Ye are from beneath; I am from above: ye are of this world; I am not of this world.
24 I said therefore unto you, that ye shall die in your sins: for if ye believe not that I am he, ye shall die in your sins.

[Ye are from beneath] A difference in responsiveness. You are of earth and respond to earthly things. By being unresponsive to heavenly things, by rejecting the Gift of God, you condemn yourselves to die in your sins.

25 Then said they unto him, Who art thou? And Jesus saith unto them, Even the same that I said unto you from the beginning.

[Who art thou?] According to verse 13 there were Pharisees (one of the most strict and respected groups of the Jewish religion) in the crowd. They were not accustomed to hearing such blunt talk directed their way. To paraphrase the exchange; "Who do you think you are?" "Just as I told you - I am the light of the world - the Christ - the Savior of mankind."

26 I have many things to say and to judge of you: but he that sent me is true; and I speak to the world those things which I have heard of him.

[I have many things to say and to judge of you] I could speedily expose all of your iniquities - your pride and ambition, your hypocrisy and irreligion, your hatred to the light, your malice against the truth together with the present obsitnate unbelief of your hearts, and show that these are the reasons why you will die in your sins.

[I speak...those things which I have heard of him] Rather than argue with a segment of the population it is more profitable that I communicate to the world the truth of him that sent me.

27 They understood not that he spake to them of the Father.

Their hearts had already rejected Jesus as the Son of God, sent from the Father.

28 Then said Jesus unto them, When ye have lifted up the Son of man, then shall ye know that I am he, and that I do nothing of myself; but as my Father hath taught me, I speak these things.

[When ye have lifted up] With the passage of time the truth will become known. Christ's crucifixion was an event required by the mercy of God, nevertheless willingly entered into by those who rejected Christ as the Mesiah. Subsequent objective examination of the facts convinces us that Jesus is the Son of God, as he said, and that his teaching is the very truth of God, making known God's love for us. Eventually all will acknowledge. The timing is critical. See Romans 14:10-11 and Philippians 2:5-11.

29 And he that sent me is with me: the Father hath not left me alone; for I do always those things that please him.

[The Father hath not left me alone] Though you shall have the power to put me to death, yet this shall not be because he has abandoned me. No - he is ever with me because I do that which pleases him, and it is his pleasure that I should lay down my life for the salvation of the world.

30 As he spake these words, many believed on him.

The same sun that hardens clay softens wax. This discourse, which reinforced the determination of the Pharisees to put Jesus to death, became the savor of life to those with open hearts.