"Then the Lord sent fiery serpents among the people, and they bit the people, so that many people of Israel died....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.'" (Numbers 21:6, 8)
We are all familiar with the story of the Israelites in the wilderness with their impatience before God and their rebellion against God. God's judgment was to send the fiery serpents to bite the people and kill them. But when they cried out to the Lord, God provided a way of salvation. His answer was the snake on the pole.
While reading this story again recently a question surfaced in my mind of how odd it seemed (at first) for God's remedy to be what it was. He told Moses to put the very thing that was killing them on the pole to provide them a way to be healed from death to life. Why, I asked myself, did God not instruct Moses to put a lamb on the pole? The obvious symbolism of this Old Testament story is Christ's saving work on the cross for us. He himself tells us that in John 3:14-15: "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." If Jesus is the Lamb slain from the foundation of the world, why didn't God use that typology for healing from the serpents' stings?
As I continued to meditate on this Scripture God graciously directed my mind to other New Testament passages to show that His choice of the serpent on the pole was the exact representation of Christ's saving work on the cross. For not only did "He himself [bear] our sins in his body on the tree," but God also "made him to be sin who knew no sin, so that in him we might become the righteousness of God." God made Jesus "to be sin," i.e., He became the very thing that was killing us on the cross in order to bring us life from the sting of sin, death.
Moses' message to the dying Israelites was: "Look to the serpent on the pole and you will be saved." Our message is the same to a dying world as we plead with them to look to Jesus and be saved.