Numbers 21:6-9 New International Version (NIV)
6 Then the Lord sent venomous snakes among them; they bit the people and many Israelites died. 7 The people came to Moses and said, “We sinned when we spoke against the Lord and against you. Pray that the Lord will take the snakes away from us.” So Moses prayed for the people.
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.
God used poisonous snakes to punish the people for their unbelief and complaining. There were a variety of snakes. Some hide and attack without warning. When the bronze snake was hung on the pole, the Israelites did not know the fuller meaning Jesus Christ would bring to this event. Jesus said that just as the Israelites were healed of their sickness by looking at the snake on the pole, now, all believers today can be saved from the sickness of sin by looking to Jesus’ death on the cross. God heals from your belief. Belief demonstrates obedience. Always continue to look to Christ.