Gospel (Jn 3:14-21)
No one has ascended into heaven except he who descended from heaven, the Son of Man. And as Moses lifted up the serpent in the wilderness, so must the Son of Man be lifted up, that whoever believes in him may have eternal life.
“For God so loved the world, that he gave his only Son, that whoever believes in him should not perish but have eternal life. For God did not send his Son into the world to condemn the world, but in order that the world might be saved through him. Whoever believes in him is not condemned, but whoever does not believe is condemned already, because he has not believed in the name of the only Son of God. And this is the judgment: the light has come into the world, and people loved the darkness rather than the light because their works were evil. For everyone who does wicked things hates the light and does not come to the light, lest his works should be exposed. But whoever does what is true comes to the light, so that it may be clearly seen that his works have been carried out in God.”
“Rejoice, O Jerusalem.” The first words of the entrance antiphon in Latin are used as the name for this fourth Sunday in Lent, which is called Laetare Sunday. It is a Sunday of joy, as Holy Week draws steadily closer. It is a joy that the liturgy can express even in the rose-colored chasuble worn by the celebrant at Mass.
The first reading recalls the sorrow of the Chosen People during their exile in Babylon, and how they were freed from slavery and allowed to return to Jerusalem thanks to King Cyrus. That king, a foreigner to the Jewish people, carries out the divine will, which shows us the universality of God’s plan for salvation (cf. 2 Chr 36:14-23).
The poetic and dramatic words of the Psalmist express the exiles’ suffering: “By the waters of Babylon, there we sat down and wept, when we remembered Zion” (Ps 137:1). The people’s nostalgic longing for Zion, the original name for the citadel of Jerusalem, is a longing for God. The Church is prefigured here, open to all nations, and the new City of God. Through divine mercy, we will one day dwell in Heaven in Christ Jesus, as the second reading assures us (cf. Eph 2:4-10).
From Heaven the Son of Man has come down to us. Today’s gospel comes at the end of Nicodemus’s visit to Jesus. The pole on which Moses raised up the bronze serpent in the desert is seen as a sign of salvation (cf. Num 21:4-9, interpreted as a sign of mercy in Wis 16:7). Jesus will be raised up on the Cross. Here he reveals to Nicodemus the central mystery of the redemption: “God so loved the world that he gave his only Son” (Jn 3:16). Our Lord proclaims the salvific meaning of the Incarnation: whoever believes in Him is saved and will enter into Heaven, into eternal life, “through faith” (Eph 2:8). To reject faith in Christ is to reject salvation.
Saint Josemaria sums up the mystery of the Crucified Saviour: “Jesus on the Cross, with his heart overflowing with love for all mankind.” Christ’s death on the Cross is the sign of God’s love, and will draw all men and women to Himself.
Nicodemus had gone to see Jesus “at night” (Jn 3:2); as yet he didn’t belong to the light. The light, the first gift of the Creator, is the source, condition and symbol of all life, and hence of salvation and joy. To this day no scientist has been able to explain exactly what light is. But a Christian knows who it is. Christ is the Light (cf. Jn 8:12; 1 Jn 1:6), and “whoever does what is true comes to the light” (Jn 3:21). To act according to a sincere conscience, discerning good from evil, is to act according to faith and open oneself to the One who came “that the world might be saved through him” (Jn 3:17).
The joy of the redemption, and therefore of union with God, is also the joy of our union with others. In the Eucharist, the Holy Spirit give us his Love, in order to share with others the joy of knowing we are loved. To smile when we are tired, to grow old with a sense of humor, to avoid centering our conversations on sad topics, to rejoice in what is good, to enjoy the company of other and share in their life as “a time of encounter”: joy is a way of loving others in God.
 Saint Josemaria, Christ is Passing By, no. 165.
 Cf. Francis, Enc. Fratelli tutti, no. 66.