Jesus is explicitly claiming to be God and the Messiah to the Jews.
Light (vv. 12-30)
God is light (1 John 1:5). The light of the world light is good and from God, and the glory of God. The messiah will the the light of the world - referring to (2 Samuel 22:29, 23:4; Psalm 77:18; Isaiah 42:6, etc...)
The Pharisees called him a liar, claiming that he was giving witness to himself only, which was not valid in court, because two witnesses were needed. When they asked, "Where is your father?", they were asking for his witness. Himself and God the Father are the two witnesses necessary. God did testy to Jesus in the Old Testament, as well as at his baptism and transfiguration.
When he says "die in your sin", the word sin here is singular, the sin of unbelief. Claiming he was not of this world, and sent by the heavenly Father, is claiming to be divine. In verse 28, "lifted up" has a double meaning of things that should be opposites. It usually means exalted, but here it also means lifted up on the cross for crucifixion. Therefore, he will be exalted when most humiliated by being tortured to death. In verse 30 we find that Jesus' word brings faith.
Truth (vv. 31-38)
Jesus is God. If you abide in his teaching, you are a disciple. If your father is the devil, then you cannot believe. Baptizing makes you become a son of God. Teaching always goes with it, just like in the Great Commission.
John 8:31b-32
“If you abide in my word, you are truly my disciples, and you will know the truth, and the truth will set you free.” –ESV
“If you hold to my teaching, you are really my disciples. Then you will know the truth, and the truth will set you free.” –NIV
“If ye continue in my word, then are ye my disciples indeed; and ye shall know the truth, and the truth shall make you free.” –KJV
“If you continue in my word, you are truly my disciples; and you will know the truth, and the truth will make you free.” –NRSV
“You are truly my disciples if you remain faithful to my teachings. And you will know the truth, and the truth will set you free.” –NLT
μένω (meno): remain, stay, wait, abide: acknowledge, respect, accept, hold to, stick to, stand by, keep to, conform to, defer to, observe, follow, heed, and act in accordance with
λόγος (logos): word (reasoning expressed by words), speech to a conclusion, message, divine utterance (the Son expressing the thoughts of the Father through the Spirit)
μαθητής (mathétés): disciple, learner, pupil, student of
God's truth is not a philosophical truth, but a truth that leads to salvation. John begins with stating Jesus is the Word of God made flesh. God can speak only truth, Jesus is "Truth" God is the God of truth, and the Lord God speaks only truth, all truth comes from God (1 Kings 17:24, Isaiah 45:19, Isaiah 65:16)
Jesus stating that he is both light and truth together is also claiming to be God, "Send out your light and your truth; let them lead me; let them bring me to your holy hill and to your dwelling!" -Psalm 43:3
I AM (48-59)
48: They don;t really think he is a Samaritan, but means that he is lax in the law
52: Jesus is "life"
53: expected the answer no, but gave the answer yes, greater than Abraham
Jesus said to them,“Truly, truly, I say to you, before Abraham was, I am.” vs. 58
Calling himself I am was referring to him being the God of the Old Testmanet: "Then Moses said to God, “If I come to the people of Israel and say to them, ‘The God of your fathers has sent me to you,’ and they ask me, ‘What is his name?’ what shall I say to them?” God said to Moses, “I am who I am.” And he said, “Say this to the people of Israel, ‘I am has sent me to you.’” -Exodus 3:13-14