in the old testament, the Israelites in the desert sinned and God sent venemous snakes among them which were biting them. Moses asked God for mercy, and He said to make a bronze serpent and raise it on a pole, and that anyone who looked on it will live, despite being bitten.

Jesus said that in the same way, He had to be raised from the earth, so that whoever is bitten by their sin can look to Him and live. Whoever believes in Jesus will have eternal life