Jn 3:13-17
[Jesus said to Nicodemus,] 13“No one has gone up to heaven except the one who has come down from heaven, the Son of Man. 14And just as Moses lifted up the serpent in the desert, so must the Son of Man be lifted up, 15so that everyone who believes in him may have eternal life.”
16For God so loved the world that he gave his only Son, so that everyone who believes in him might not perish but might have eternal life. 17For God did not send his Son into the world to condemn the world, but that the world might be saved through him.
Everyone who Believes in Him may have Eternal Life: To believe (Greek pisteuein) is a key concept in the Gospel of John and appears throughout the Gospel. One can say that for the evangelist, there are only two commandments of Jesus: to believe and to love. Faith is connected with and is the condition for salvation. Everyone who believes in Jesus has eternal life. John writes his Gospel “that you may come to believe that Jesus is the Messiah, the Son of God, and through this belief you may have eternal life in his name” (Jn 20:31).
Faith in Jesus is not primarily a matter of assent to his teaching, but trust and union with him. It is readiness to share his destiny and to accept his “hard teachings.” Human intention and efforts alone are not enough to believe. Faith is primarily a gift of God. No one can come to Jesus unless the Father draws him (Jn 6:44).
In his conversation with Nicodemus, Jesus speaks of the bronze serpent lifted up by Moses in the desert (Nm 21:4-9). The Israelites who were wandering in the desert were losing their faith and rebelled against God and against Moses. In punishment, the Lord sent saraph serpents which bit the people so that many of them died. When the people repented, God ordered Moses to make a bronze serpent and mount it in a pole. Anyone who had been bitten and looked at the bronze serpent recovered.
The mounted pole, for the evangelist, is the image of Jesus “mounted” on the cross of Calvary. Those who gaze at the crucified Jesus with faith will have eternal life. For the cross is the sign of God’s love for the world. The cross, formerly a symbol of shame, cruelty, and curse, becomes an instrument of victory and life.