John 8:28

‘So Jesus said, ‘When you have lifted up the Son of Man, then you will know that I am, and that I do nothing of myself but say just what my Father has taught me'.

Jesus now again faces them up to what He knows they are going to do with Him. He knows that His days are numbered. But He also knows that this will be for the good of those who respond to Him.

‘When you have lifted up the Son of Man.' Note His claim again to be the Messianic Son of Man. The phrase ‘lifted up' occurs a number of times in John's Gospel. In John 3:14 it refers to His crucifixion, but must contain the seeds of His glorification, for His lifting up will offer eternal life to those who believe in Him. In John 12:32 it is specifically stated to also refer to His crucifixion, but again must include the idea of His glorification, for how else could He draw all men to Him? Thus here it is probably intended again to include both, while considering mainly the latter. Without being aware of it they will contribute both to His lifting up in death and His lifting up in resurrection and exaltation.

The phrase was deliberately vague, and had a deliberate dual meaning. Jesus could not say blatantly ‘when you have killed me' (for the sake of the listening crowds), and besides that would only have signified one aspect of His death. He wanted to present His death both in its starkness and in its triumph. So ‘lifted up' stressed both those things. He would be lifted up as a public spectacle, like the golden serpent (John 3:14), and yet also He would be lifted up to God.

The words here are general and not specific. ‘You' refers to the Jews as a whole, yes, and even to the world. Their main significance is for those who would later believe, and there were many. It is they who will come to know that Jesus is the ‘I am', and that He reflected His Father's will. So His death will be a triumph because for many it will result in belief and understanding. But the Pharisees as a whole will know it in a more general sense when they see the impact of His death and resurrection. Then they too will have to face up to the truth about Him, even though they finally reject it.

We may compare this with the idea in Matthew 26:64 (compare Luke 22:69), when He says, again to the Jewish leaders, ‘From now on you will see the Son of Man sitting at the right hand of power and coming on the clouds of Heaven', where the point was that while they themselves would not respond to His being made Lord, they would see that there would be many who would. They would be aware of His impact as the Son of Man.

‘That I am.' The Pharisees would understand this as meaning ‘that I am the Coming One.' But the writer wants us to see the deeper meaning, ‘that I am the “I am”.' (John 8:58).