During the general audience on 15 November, the Holy Father considered the effect of Peter's discourse at Pentecost upon those who heard him.

1. After recording Peter's first discourse on the day of Pentecost, the Author of Acts informs us that those present "were cut to the heart" (Acts 2:37). They are eloquent words which indicate theaction of the Holy Spirit in the souls of those who heard from Peter the first apostolic preaching, his witness concerning Christcrucified and risen, his explanation of the extraordinary events which had taken place that day. In particular, that first public presentation of the paschal mystery reached the very core of the expectations of the people of the Old Covenant, when Peter said: "God has made both Lord and Christ this Jesus whom you crucified" (Acts 2: 36).

The same Holy Spirit who had descended upon the apostles was now at work in the hearts of those who heard the apostolic preaching. Peter’s words touched their hearts, awakening in them "a conviction of their sinfulness", the beginning of conversion.

2. Filled with remorse, "...they said to Peter and the rest of the apostles: 'Brethren, what shall we do?’ " (Acts 2:37). The question, "what shall we do?" shows their readiness of will. It was the interior good predisposition of Peter’s listeners that, on hearing his words, made them aware that it was necessary to change their lives. They addressed Peter and the other apostles, because they knew that Peter spoke in their name also, and that "the eleven" therefore (that is to say, all the apostles) were witnesses of the same truth and were charged with the same mission. It is also significant that they called them "brethren", echoing Peter who had spoken in a fraternal spirit in his discourse, in the latter part of which he addressed those present as "brethren ".

3. Peter himself now replies to the question of those present. It is a very simple reply which could well be described as lapidary: "Repent" (Acts 2:38). It was with this exhortation that Jesus had begun his messianicmission (cf. Mk 1:15). Now Peter repeats it on the day of Pentecost, in the power of the Spirit of Christ who descended on him and on the other apostles.

Repentance, as I emphasized in the Encyclical Dominum et Vivificantern, is the crucial step in the process of conversion which the Holy Spirit works within us: "By becoming ‘the light of hearts’, that is, the light of consciences, the Holy Spirit ‘convinces concerning sin’, which is to say, he makes man realize his own evil (i.e. the evil committed by himself), and at the same time directs him towards what is good... . Thus the conversion of the human heart, which is an indispensable condition for the forgiveness of sins, is brought about by the influence of the Counsellor" (n. 42).

4. "Repent", on the lips of Peter means: change from the rejection of Christ to faith in the Risen One. The crucifixion had been the definitive expression of the rejection of Christ, sealed by an ignominious death on Golgotha. Now Peter exhorts those who crucified Jesus to have faith in the Risen One: "God raised him up, having loosed the pangs of death" (Acts 2:24). Pentecost, then, was the confirmation of Christ's resurrection.

The exhortation to conversion implies above all faith in Christ the Redeemer. Indeed, the resurrection is the revelation of that divine power which, by means of Christ’s crucifixion and death, effects man's redemption and his liberation from sin.

If through Peter’s preaching the Holy Spirit "convinces concerning sin", he does so "by virtue of the redemption accomplished by the blood of the Son of man.... The Letter to the Hebrews says that this ‘blood purifies the conscience’(cf. 9:14). It therefore, so to speak, opens to the Holy Spirit the door into man's inmost being, namely, into the sanctuary of human consciences" (Dominum et Vivificantem, 42).

This profound and inmost level, Peter proclaims and testifies in his Pentecost discourse, is reached by the action of the Holy Spirit in virtue of Christ’s redemption.

5. Peter goes on to complete his message as follows: "Repent, and be baptized every one of you in the name of Jesus Christ for the forgiveness of your sins; and you shall receive the gift of the Holy Spirit" (Acts 2:38). Here we have the echo of what Peter and the other apostles heard from Jesus after his resurrection, when "he opened their minds to understand the scriptures, and said to them, ‘Thus it is written, that the Christ should suffer and rise from the dead... and that repentance and forgiveness of sins should be preached in his name to all nations, beginning from Jerusalem’ ".(Lk 24:45-47).

Following faithfully what Christ had laid down (cf. Mk 16:16; Mt 28: 19), Peter calls not only for "repentance" but also for baptism in Christ’s name "for the forgiveness of... sins" (Acts 2:38). In fact, the apostles on the day of Pentecost were "baptized in the Holy Spirit" (cf. Acts 2:4). Therefore, in passing on the faith in Christ the Redeemer, they urge people to be baptized, for baptism is the first sacrament of this faith. Since it effects the forgiveness of sins, the faith should find in baptism its own sacramental expression so that man may share in the gift of the Holy Spirit.This, we may say, is the ordinary way of conversion and grace. Other ways are not excluded, for "the Spirit blows where it wills" (cf. Jn 3:8) and can accomplish the work of salvation by sanctifying man apart from the sacrament, when its reception is not possible. It is the mystery of the meeting between divine grace and the human soul. Let this reference suffice for the moment, for we shall speak about it again, God willing, in the reflections on baptism.

6. In the Encyclical Dominum et Vivificantem I analysed the victory over sin won by the Holy Spirit in reference to the action of Christ the Redeemer. There I wrote: "The convincing concerning sin, through the ministry of the apostolic kerygma in the early Church, is referred—under the impulse of the Spirit poured out at Pentecost—to the redemptive power of Christ crucified and risen. Thus the promise concerning the Holy Spirit made before Easter is fulfilled: ‘He will take what is mine and declare it to you’. When therefore, during the Pentecost event, Peter speaks of the sin of those who ‘have not believed’ and have sent Jesus of Nazareth to an ignominious death, he bears witness to victory over sin: a victory achieved, in a certain sense, through the greatest sin that man could commit: the killing of Jesus, the Son of God, consubstantial with the Father! Similarly, the death of the Son of God conquers human death: ‘I will be yourdeath, O death’, as the sin of having crucified the Son of God ‘conquers’ human sin! That sin which was committed in Jerusalem on Good Friday—and also every human sin. For the greatest sin on man's part is matched, in the heart of the Redeemer, by theoblation of supreme love that conquers the evil of all the sins of man" (n. 31).

It is therefore a victory of love! This is the truth contained in Peter’s exhortation to conversion through baptism.

7. By virtue of Christ’s victorious love the Church also is born in the sacramental baptism through the work of the Holy Spirit on the day of Pentecost, when the first conversions to Christ took place.

We read in fact that "those who received his word (that is, the truth contained in Peter’s words) were baptized, and there were added that day about three thousand souls" (Acts 2:41): that is, "they were added" to those who had been previously "baptized in the Holy Spirit, the apostles. Having been baptized "with water and the Holy Spirit", they become the community "of the adopted sons of God" (cf. Rom 8:15). As "sons in the Son" (cf. Eph 1:5) they become "one" in the bond of a new brotherhood". Through the action of the Holy Spirit they become the Church of Christ.

8. In this regard one must recall the event concerning Simon Peter which took place on the lake of Gennesaret. The Evangelist Luke tells us that Jesus "said to Simon, ‘Put out into the deep and let down your nets for a catch’. And Simon answered, ‘Master, we toiled all night and took nothing! But at your word I will let down the nets’. And when they had done this, they enclosed a great shoal of fish, and their nets were breaking... and they filled both the boats, so that they began to sink. But when Simon Peter saw it, he fell down at Jesus’ knees, saying, ‘Depart from me, for I am a sinful man, O Lord’.... And Jesus said to Simon, ‘Do not be afraid; henceforth you will be catching men’. And when they had brought their boats to land, they left everything and followed him" (Lk 5:4-8: 10-11).

In that event-sign there was the announcement of the future victory over sin through faith, repentance and baptism, preached by Peter in Christ's name. That announcement became reality on the day of Pentecost, when it was confirmed by the work of the Holy Spirit. Peter the Fisherman and his companions of the lake of Gennesaret found in this reality the paschal expression of Christ’s power, and at the same time the meaning of their apostolic mission. They found the fulfilment of the announcement: " From now on you will be a fisher of men".