The Israelites were being attacked by poisonous snakes as punishment for complaining against God. God instructed Moses to make a bronze serpent and mount it on a pole. Anyone who was bitten just needed to look at the bronze serpent to be healed. Jesus later referred to this story, saying he must be "lifted up" like the bronze serpent so that all who believe in him will have eternal life. All that is required is to accept Jesus into your heart to receive salvation and everlasting life.