Joh 3:14-15, 14 And as Moses lifted up the serpent in the wilderness, even so must the Son of Man be lifted up 15 that whoever believes in Him should not perish but have eternal life.
The Israelites were rebellious, they spoke against God and Moses (Num 21). God sent fiery serpents to bite and kill them, but then Num 21:8 “…the Lord said to Moses, “Make a fiery serpent, and set it on a pole; and it shall be that everyone who is bitten, when he looks at it, shall live.” God who plagued also provided a remedy, a bronze serpent lifted up by Moses on a pole that whoever looked upon it was healed and lived.
Jesus refers to the serpent. As Israel needed the bronze serpent on a pole to live, we needed Jesus lifted up on the cross to die for our salvation. But how can a serpent have similarity to Jesus? “The serpent signified Christ, who was in the likeness of sinful flesh, though without sin, as this brazen serpent had the outward shape, but not the inward poison, of the other serpents: the pole resembled the cross upon which Christ was lifted up for our salvation: and looking up to it designed our believing in Christ” (John Wesley).
Jesus alone lifted up on the cross is the hope for everyone. “For He made Him who knew no sin to be sin for us, that we might become the righteousness of God in Him” (2Cor 5:21); “For the message of the cross is foolishness to those who are perishing, but to us who are being saved it is the power of God” (1Cor 1:18). Point no. 2, The gospel that saves must be cross centered.