12 Then Jesus spoke to them again, saying, “I am the light of the world. He who follows Me shall not walk in darkness, but have the light of life.”
13 The Pharisees therefore said to Him, “You bear witness of Yourself; Your witness is not true.”
14 Jesus answered and said to them, “Even if I bear witness of Myself, My witness is true, for I know where I came from and where I am going; but you do not know where I come from and where I am going.
15 You judge according to the flesh; I judge no one.
16 And yet if I do judge, My judgment is true; for I am not alone, but I am with the Father who sent Me.
17 It is also written in your law that the testimony of two men is true.
18 I am One who bears witness of Myself, and the Father who sent Me bears witness of Me.”
19 Then they said to Him, “Where is Your Father?” Jesus answered, “You know neither Me nor My Father. If you had known Me, you would have known My Father also.”
20 These words Jesus spoke in the treasury, as He taught in the temple; and no one laid hands on Him, for His hour had not yet come.
spoke to them (verse 12) — the people from verse 2
light (John 1:6-8) — Jesus is the source of light. Apart from Him, there is darkness.
I Am the light — the second "I Am" in John. I, the LORD, have called You in righteousness, and will hold Your hand; I will keep You and give You as a covenant to the people, as a light to the Gentiles (Isaiah 42:6).
It also shows His deity. God is said to be three things: 1) light — 1 John 1:5, 2) spirit — John 4:24, 3) love — 1 John 4:8
of the world (verse 12) — but only believers are saved (John 12:46)
follows (verse 12) — believes
Verse 13 proves John 1:5 — And the light shines in the darkness, and the darkness did not comprehend it.
You do not know (verse 14) — They didn't know who He was or they wouldn't have accused Him of bearing false witness.
Though I bear record of Myself yet My record is true." Some have experienced a difficulty in harmonizing this with what we read of in 5:31 — "If I bear witness of myself, my witness is not true." But if each of these statements be interpreted in strict accord with the context the difficulty vanishes. In John 5 the Lord was proving that the witness or record He bore was not in independece of the Father, but in perfect accord therewith. The Father Himself (5:37) and the Scriptures inspired by the Father (5:39) also testified to the absolute deity of Christ. But here in John 8 the Lord Jesus is making direct reply to the Pharisees who had said that His witness was false. This He denies, and insists that it was true; and immediately after He appeals again to the confirmatory witness of the Father (see 8:18). Exposition of the Gospel of John, by Arthur W. Pink, page 29
according to the flesh (verse 15) — based on outward appearance. You have formed your estimate of Me based on appearances, but I do not form my estimates in that way but on truth.
if I judge (verse 16) = when I judge
judge (verse 16) = determine, form an estimate, arrive at a decision
your law (verse 17) — Deuteronomy 17:6-19:15
If you had known me (verse 19) — the Father can only be known through the Son and to know the Son is to know the Father.
treasury (verse 20) — part of the temple where women were allowed. There were 13 trumpet-shaped containers for offerings, nine for legal payments and four for free-will offerings.
John writes about the deity of Jesus — what He was in Himself and not just what He was to the Jews, as in the other Gospels.