In John chapter 8, Jesus addressed the Jews in Jerusalem who didn’t believe that He was God’s Son or that He had been sent by the Father and would soon to return to His Father. His proof may seem odd to us at first.
Jesus said to them, “When you have lifted up the Son of Man, then you will know that I am he….” (John 8:28, ESV)
Why is it that Jesus’ otherworldly identity would be confirmed when He was “lifted up” to die?
John presents this story about Jesus being lifted up so that we might believe that Jesus is the Son of God because the nature of sacrifice comes from the nature of God.
When God (the Son) is killed you’ll recognize (that Jesus is) God. Why? Because not only is God strength, He is sacrifice. When the Father sent the Son on mission with authority (note the first half of verse 28), His authority got Him to the precise place He wanted to be: a throne through sacrifice. Jesus spoke what the Father taught Him (see the second half of verse 28). What were those eternal sessions about? What were the unit objectives? Divine glory through sacrifice. What does Jesus reveal? What the Father told Him, that the nature of greatness comes through sacrifice and service, not being served. How could the Son being lifted up, being killed, please the Father since He “always [does] the things that are pleasing to Him” (a fact mentioned in verse 29)? His death has to be part of the “always,” right? It’s because sacrifice is what God does. Loving sacrifice is the way of the Trinity, not just an idea they came up with for someone else to try.
After the cross we look back to the cross as the divine story of sacrifice. We see little sacrifices by men as echoes of that great sacrifice by the Son of Man. But what kind of God comes up with that sort of narrative? A God whose nature is loving sacrifice. It’s part of the reason that the Jewish religious authorities couldn’t recognize God in flesh: He was serving too many other people. They believed the lie that getting is better than giving. They couldn’t bear to hear Jesus’ words (8:43) because they were listening to their father, a murderer from the beginning (8:44).
The serpent took life, He did not give his life so that others could have life. The serpent made no sacrifice because he only had eyes for himself.
The Father and the Son reveal otherworldly lessons about what really pleases God: sacrifice. It’s part of His nature and Jesus was the fullness of deity dwelling bodily. There was no more clear revelation of His deity than when He was lifted up on the cross. There was no greater pleasure that the Son brought the Father than when He was lifted up on the cross.
Christ’s sacrifice for undeserving sinners proved His identity. Likewise, our sacrifice for undeserving sinners proves our identity as Christians.