What does John 8:57 mean?

A common theme in Jesus' interaction with others was that of misunderstanding. More often than not, that misunderstanding was a result of interpreting Jesus' words in an overly literal, physical sense when they were meant to be understood in a spiritual sense. The problem here, of course, was not that His critics lacked intelligence or education (Matthew 16:1; 19:3; 22:35; Luke 10:25; 11:53–54). On the contrary, they had all of the evidence they could possibly need. This included Scripture (John 5:39–40) and miracles (John 5:36). Their refusal to accept Christ was just that—refusal—which is what caused their mistakes. In other words, they did not understand because they refused to obey. Their hatred for the truth made it impossible for them to grasp Jesus' message (John 7:17; 8:43).

In the prior verse, Jesus referred to Abraham, noting that even he looked forward to the coming of a Promised One. That person, according to Scripture and evidence, is Jesus Himself. But the remark made by Jesus implies the same idea He spoke of in verse 55: that His knowledge is personal, direct, and innate. This leads to another misunderstanding, delivered with palpable sarcasm: "Abraham has been dead for thousands of years, how can you claim to have seen him?" The answer Jesus gives will not only summarize His teaching, it will outrage His critics to the point of physical attack.