8 The Lord said to Moses, “Make a snake and put it up on a pole; anyone who is bitten can look at it and live.” 9 So Moses made a bronze snake and put it up on a pole. Then when anyone was bitten by a snake and looked at the bronze snake, they lived. (Numbers 21:8-9, NIV)
Compare this with what Jesus said in John 3:14-15.
14Just as Moses lifted up the snake in the wilderness, so the Son of Man must be lifted up, 15that everyone who believes may have eternal life in him."