What does John 8:55 mean?

Any illusions that Jesus was timid, weak, or passive are destroyed when a person actually reads the Gospels. In particular, the gospel of John shows that Jesus was willing to be forceful and direct when necessary. Jesus drove corrupt businessmen out of the temple with a whip (John 2:13–22). He easily handled the challenges of public debate (Matthew 16:1; 19:3; Matthew 22:35; Luke 10:25; 11:54). Earlier in this conversation, He referred to His critics as the sons of the devil (John 8:44). Here, Jesus is as forceful and direct in His condemnation as anywhere in the Bible.

In short, Jesus has knowledge of God and teaches the message God wants the world to hear. The men opposing Him (John 8:13), insulting Him (John 8:41, 48), and trying to kill Him (John 8:59) are not. This is because Jesus knows God and represents truth. These critics are liars who do not know God.

In Greek, the statement Jesus makes here implies a difference even deeper than what's implied in English. When Jesus refers to his critics, He states that they have not "come to know" God, using the Greek root word ginosko. This is a knowledge gained by observation and experience. But, when speaking of His own knowledge, Jesus uses the Greek root word eido, which is knowledge that's intuitive, inherent, or natural. In other words, these men haven't even encountered or learned about God, while Jesus has personal, direct knowledge of Him. The gulf between Christ's understanding of God and their understanding is not just intellectual, and not just spiritual. The difference is fundamental: Jesus knows God because He is God. This is a point Jesus will make very directly in the upcoming verses, enraging His critics.