Again Jesus spoke to them, saying, “I am the light of the world. Whoever follows me will never walk in darkness but will have the light of life.”
Then the Pharisees said to him, “You are testifying on your own behalf; your testimony is not valid.”
Jesus answered, “Even if I testify on my own behalf, my testimony is valid because I know where I have come from and where I am going, but you do not know where I come from or where I am going. You judge by human standards; I judge no one. Yet even if I do judge, my judgment is valid; for it is not I alone who judge, but I and the Father who sent me. In your law it is written that the testimony of two witnesses is valid. I testify on my own behalf, and the Father who sent me testifies on my behalf.”
Then they said to him, “Where is your Father?” Jesus answered, “You know neither me nor my Father. If you knew me, you would know my Father also.” He spoke these words while he was teaching in the treasury of the temple, but no one arrested him, because his hour had not yet come.
— John 8:12-20 (NRSV)
I assume — perhaps incorrectly — that the analogue passage from the Synoptics may be of some help as a dialogue partner to folks:
“You are the light of the world. A city built on a hill cannot be hid. No one after lighting a lamp puts it under the bushel basket, but on the lampstand, and it gives light to all in the house. In the same way, let your light shine before others, so that they may see your good works and give glory to your Father in heaven.
— Matthew 5:14-16 (NRSV)