What a wonderful reminder of the thoroughness of God's design - all along He had this son Jesus in mind through whom He would redeem the creation.
There could be no redemption under the Old Cov. yet the big figures like David and Abraham and several others had a glimpse of what, and possibly who was coming. They understood that they too were a part of the age of Jesus.
‘Your father Abraham was overjoyed that he would see my day, and he saw it and rejoiced.’ John 8:56
Before continuing with the answer, a quick reminder about understanding the bible. As noted below in Link 1, we must not know anything unless there is support from other biblical texts for an idea or belief. If there are texts that oppose our understanding, we have got something wrong and need to realign our position to be sure every text agrees with the passage in mind.
There no mention of Jesus before his conception and subsequent birth (~4BC) except in prophecy.
Jesus is not mentioned in John 1:1-3 because John is not talking about Jesus. (does it say ‘Jesus’? No, it does not. Does it mean Jesus? No, it does not. Do we read Jesus? Yes, some do – why? Go figure!
John is taking about logos in that passage and later on he puts the focus on Christ. If we choose to read in whatever we like we are just adding confusion.
Anyway, what does before Abraham mean?
Paul gives a clue in Gal 3:16
The promises were spoken to Abraham and to his seed. Scripture does not say "and to seeds," meaning many people, but "and to your seed," meaning one person, who is Christ.
So, quite unequivocally, Paul tells us what the ‘before’ means. Jesus was the one to come, yet he was planned well before Abraham existed. He would be the descendant of Abraham!
Our texts do not say, ‘before Abraham, I existed’.
The phrase egō eimi or ‘I am’ is used a bit in the NT by other people who certainly are not God or claiming to be God. To hang desperately to this one “I am” is to ignore other texts that are exactly the same and simply refer to the person in context. Jesus is saying nothing more than “I am the one”, “It is I”. Before Abraham, ‘I am the one’ that he looked forward to. ‘My day’, had just begun!
The man born blind John 9:9, ‘I am (he)’ egō eimi
Matt 14:27 Take courage, it is I. Don’t be afraid. Mk 6:50 John 6:20 egō eimi
The disciples said, ‘Surely you don't mean me, Lord?" egō eimi
John 8:28 ‘you will know that I am he…’ egō eimi
While it’s tempting to cling to this ‘I am’ construct, it must align with the rest of the NT. Which is silent on Jesus being God from Matt to Rev.
To think that Jesus is claiming to be God is absurd – considering that he does so nowhere else, no apostle affirms this idea, but we have a consistent record of him claiming to be God’s human son, the Messiah, the one God sent, the one the Jews/Israelites were waiting for. Unfortunately, when he finally arrived, he was bringing in a new way of doing things – the law of sin and death was being superseded and they – the masters of the law, were out in the cold!
It’s also absurd as Jesus consistently has a God – the same God as everyone else. Does God have a God? Not unless one wants to twist the scriptures and play games with fanciful concepts not of the inspired text. Of course, God doesn’t have a God. We also know God cannot be tempted or sin or die – Jesus was tempted, he did die and when raised and exalted to God’s right hand and made heir to all God’s stuff God called His angels to worship him. This is all plainly revealed, yet stubborn ideas introduced 100’s of years after the cannon still sadly guide men’s faith and beliefs.
Let’s walk through the passage that ends with, ‘they picked up stones to throw at Him’.
The Jews were bewildered by the events regarding Jesus - they saw their eyes and heard with their ears but their minds could not grasp what was going on.
v48 They say Jesus has a demon… wrong!
v51 Jesus informs that he has the power of life – if people keep his word. They say he is over-rating himself.
V53 they say Abraham ‘is the greatest!’ The prophets are all dead – who are you?
V54 Jesus says he doesn’t need to glorify himself – the Father will do that. He doesn’t big-note himself, just tells it like it is. He says if he doesn’t tell the truth about knowing the Father – he would be a liar.
V55, he says they don’t know who the Father is. They still call Abraham their father!
V56 Jesus puts it all in context by reminding them of the promises to Abraham God made long ago – he was the one that was promised! I am the one that was always coming. This is my day now and there will be no going back!
V58 confused and threatened by Jesus answers to their silly questions and accusations, they respond with, ‘You are not yet fifty years old, and have You seen Abraham?’
V59 Still confused and having no idea what Jesus is talking about, (just as Nicodemus thought, being born again was to re-enter the mother’s womb!) Jesus reminds them that God’s plan of which he was to be the centre was in place well before Abraham.
Their whole outlook had been challenged – perhaps, just quietly, they could feel the ‘spirit of truth’ in Jesus’ words - even though they refused to believe, they stooped to throwing stones like angry children.
Link 1 How to understand Titus 3:9?