In this section, the Israelites are going the long way around Edom, which they will not cross because the Edomites, who are the descendants of Esau, are hostile to them. This is a very harsh desert region that even now, is inhabited by several varieties of venomous snakes. As they people mover through the region, they began to gripe and complain about the conditions; they spoke harshly against both Moses (“type” of Christ) and God Himself. God, hearing their mutinous talk, sent them a plague of snakes that left many with very painful and often fatal wounds. (vv. 4-6)
Before long, the people began to repent of their rebellion and sought out intercession from Moses, who prayed to God for deliverance. God gave Moses an odd instruction: make an image of a snake, attach it to a pole and hold it up for people to see. If they looked upon the image, they would be saved from their bites and the venom of the snakes. Notice that God did not simply remove the snakes or make the people immune to their bites. (vv. 7-9)
Here, Jesus is speaking to Nicodemus, shortly after He has told Nicodemus that he must be born again to enter the kingdom of Heaven. (vv. 1-10) Of course, Nicodemus is having a hard time following Jesus’ meaning, so Jesus is trying to explain the matter further in 11-18. Jesus points out that He knows what He is talking about, because He is speaking of things He has seen (v. 11). The Gospel, from that day to this, is spread by the testimony of believers, from Jesus’ own testimony to that of the Apostles, later recorded in Scripture, and also that of believers today: You can either believe it or not. Then, Jesus says that if Nicodemus cannot understand earthly things, how can he understand Heavenly things? Up to this point, Jesus was speaking of redemption, which occurs here on earth, not in Heaven. No one, He says, has ever gone into Heaven. Note that under the covenants with both Abraham and Moses, there is no promise of either Heaven or eternal life for anybody. The only one who had ever seen Heaven was Jesus Himself, who came from Heaven. (vv. 12-13)
It is at this point in His conversation that Jesus recounts the events of Numbers 21 with regard to the snake that was lifted up. He tells Nicodemus that as the people were cured of the snake venom when they looked upon the snake, so also will they be “cured” when they look in faith at Jesus Himself, when He is lifted up. In fact, He used the words “must be lifted up” in verse 14; there is simply no other way to restore the relationship between Man and God then Jesus going to the cross. When the snake was lifted up, the onlooker was cured of the venom, but God did not remove the snakes. When Jesus was lifted up, and people look to Him on the cross in faith, God takes away the more serious venom of rebellion, but He has left the cause of it in our world; interesting! Finally, Jesus tells Nicodemus that those who believe in Him will receive “eternal life”. (vv. 14-15) This is the first time Jesus used the term “eternal life” and it is the very first time it is promised in either the Old or New Testament, chronologically speaking.
From there, Jesus builds upon His theme of His dying to give those who believe in Him eternal life. In these very familiar verses, He ties together the concept of rebirth with His death on the cross.