The Holy Spirit, in the words of Benedict XVI, is “the first and principal gift that Jesus obtained for us through his Resurrection and Ascension into heaven.”
Therefore the risen Jesus is eager to give his Spirit to the Apostles, shut in for fear of the Jews, in order to send them out as the Father had sent him, filled with his own peace, joyful and with the power to forgive sins.
This scene narrated by Saint John is closely related to the account of Pentecost in the Acts of the Apostles. As Pope Francis said: “On the evening of Easter, Jesus appeared to the Apostles and breathed on them his Spirit (cf. Jn 20:22); on the morning of Pentecost the outpouring occurred in a resounding way, like an impetuous wind that shook the place the Apostles were in, filling their minds and hearts. They received a new strength impelling them to proclaim Christ’s Resurrection in different languages.”
The scene of Pentecost recalls for us the narrative of the Tower of Babel, in which human pride was punished by the confusion of tongues and the dispersion of peoples (cf. Gen 11:1-9). Now, however, the gift of the Spirit of Love transforms division, coldness and fear into unity, charity and daring. Francisca Javiera del Valle, in her book About the Holy Spirit, says Jesus petitioned the Father from the Cross that “the Holy and Divine Spirit be sent to men, so that all those gathered together in the Word could live with one body and one soul.” While the devil separates people and fosters confrontation and violence (and therefore is called in Greek diabolos, “slanderer,” “divider”), the Spirit instead unites and fosters harmony and life.
It is the Holy Spirit who makes us realize we are children of God, who can cry out “Abba, Father!” (Rom 8:15). He infuses in us the seven gifts the Church’s tradition has singled out: “wisdom, understanding, counsel, fortitude, knowledge, piety, and fear of the Lord” (CCC, 1831). And He fills the soul with the twelve fruits Saint Paul describes to the Galatians: “charity, joy, peace, patience, kindness, goodness, generosity, gentleness, faithfulness, modesty, self-control, chastity” (CCC, 1832; cf. Gal 5:22-23). As the liturgical hymn for this day sings: “You, of comforters the best; You, the soul’s most welcome guest; Sweet refreshment here below; In our labor, rest most sweet; Grateful coolness in the heat; Solace in the midst of woe. O most blessed Light divine, May that light within us shine, And our inmost being fill!”
It is good to examine ourselves frequently on how we are letting the Holy Spirit work in our soul, whether we are following his inspirations with a docile and trusting attitude when he invites us to forgive others, to show our love and affection for God and those around us with small acts of service. The whole secret of our sanctity is summed up in being docile to the Holy Spirit. If we strive to act in this way, the Paraclete will produce the same wonders and changes that he worked in the first disciples and in the saints, and will grant us their apostolic boldness and diligence. Saint Josemaria’s advice is very timely: “Let us allow his impulse to guide our lives. Let us feed the desire to spread that divine fire throughout the world, making it known to all the people around us. Then they too can experience the peace of Christ and find happiness there.”
But the spreading of this current of love and unity, destined for all peoples and initiated on Pentecost, is possible only through the remission of sin, the origin of all evil (cf. Code of Canon Law, no. 403). Thus in the Cenacle the risen Jesus grants the Apostles the power to forgive sins, made specific later in the Sacrament of Penance (cf. Council of Trent, De Paenitentia, ch. 1). Confession is the first step needed to let the Paraclete act in our lives. Thanks to the humble and frequent confession of our sins, with a person who has authority to absolve them, what Pope Francis describes takes place: “the Spirit frees hearts chained by fear. He overcomes all resistance. To those content with half measures, he inspires whole-hearted generosity. He opens hearts that are closed. He impels the comfortable to go out and serve. He drives the self-satisfied to set out in new directions. He makes the lukewarm thrill to new dreams.”
 Benedict XVI, Homily, May 23, 2010.
 Pope Francis, Homily, May 24, 2015.
 Francisca Javiera del Valle, About the Holy Spirit, Third Day.
 Saint Josemaria, Christ is Passing By, no. 170.
 Pope Francis, Homily, May 20, 2018