Lifting up

When I was reading John 3 I noticed something that didn't stick out before. Jesus was talking with Nicky and talking about being born again and believing on Him. The he stated that, like Moses did to the serpent, believers would need to lift Him up ... Actually, here's the verse from the ESV translation:
Truly, truly, I say to you, we speak of what we know, and bear witness to what we have seen, but you do not receive our testimony. If I have told you earthly things and you do not believe, how can you believe if I tell you heavenly things? No one has ascended into heaven except he who descended from heaven, the Son of Man. And as Moses lifted up the serpent in the wilderness, so must the Son of Man be lifted up, that whoever believes in him may have eternal life. (John 3:11-15 ESV)

I think this is what Jesus is referencing:
From Mount Hor they set out by the way to the Red Sea, to go around the land of Edom. And the people became impatient on the way. And the people spoke against God and against Moses, "Why have you brought us up out of Egypt to die in the wilderness? For there is no food and no water, and we loathe this worthless food." Then the Lord sent fiery serpents among the people, and they bit the people, so that many people of Israel died. And the people came to Moses and said, "We have sinned, for we have spoken against the Lord and against you. Pray to the Lord, that he take away the serpents from us." So Moses prayed for the people. And the Lord said to Moses, "Make a fiery serpent and set it on a pole, and everyone who is bitten, when he sees it, shall live." So Moses made a bronze serpent and set it on a pole. And if a serpent bit anyone, he would look at the bronze serpent and live. (Numbers 21:4-9 ESV)

Once everyone who is bitten sees it, they shall live. Even though the are repentant, it didn't remove the punishment. But, God provides salvation from His wrath. So, we are bitten, we need to look upon Jesus who was raised up on a cross in order to live...