Twice in the book of John we have recorded Christ talking about being lifted up on a cross. Both references come from the event in Numbers 21 when the people lost confidence in God, complained and complained some more griping against Moses and against God. In judgment, God sent deadly serpents through the camp and many were bitten and died. The people repented of their sin and God told Moses to have a brass serpent made and lifted up on a pole; whoever would look at this brass serpent would live.
In this sermon, Pastor Steve ties these events together as Nicodemus would have understood them and then points us all to the Cross of Christ as the place to look in faith. (This would be a good message to have a friend listen to.)