How many times did the Holy Spirit come? Once Jesus breathed it after his resurrection, later, in Acts, the Holy Spirit comes again.
Biblical reports of the coming of the Holy Spirit are to be interpreted within the framework of the belief in the presence and acting of the Holy Spirit in the life of Christians. The Bible understands the Holy Spirit as the creative power of all life: he brings life to everything, holds everything together and guides everything towards the goal of eschatological salvation. He is active mainly in Jesus Christ: in his conception, his baptism, his public ministry, his death and his resurrection. In death, resurrection and glorification he brought about the beginning of the new creation, which one day will reach its completion in the transfiguration of everything that is. Thus, Jesus is the Christ, i.e. the one anointed with the Holy Spirit. According to the gospel of St Luke Jesus applies the promise of the prophet to himself: The Spirit of the Lord is on me, because he has anointed me (Lk 4:18; cf. Acts 10:38; Jn 1:32). Our redemption and our salvation consist in our participation in the Spirit that fills Jesus Christ. We are Christians, i.e. anointed through participating in the anointment of Christ with the Holy Spirit.
This participation in Jesus Christ is a gift from the Holy Spirit himself. Because the Spirit has been sent to actualise again and again and in perpetuity Jesus Christ, his person, his word and his acting in history. Thus, all reality is penetrated and filled with the Holy Spirit who is the spirit of Jesus Christ. Therefore, Paul can say: Now the Lord is the Spirit, and where the Spirit of the Lord is, there is freedom (2 Cor 3:17). This means: the Spirit is the active presence and the present activity of the raised Lord of the Church and of the world. He is not merely the gift of new life in Jesus Christ, he is also the giver of this gift; a separate own divine person. Where he acts the eschatological kingdom of freedom is already beginning in the here and now. The gift of the Holy Spirit received in faith is the reality of the new covenant (Thomas Aquinas).
Luke expressed the meaning of this in his report on the outpouring of the Holy Spirit at Pentecost (cf. Acts 2:1-13). For the Jews, Pentecost was originally a harvest festival. In the 1./2. century A.D. it became a day to commemorate the covenant on Mount Sinai. Luke follows on from this. With his report on the outpouring of the Holy Spirit he wants to depict the beginning of the final salvific period, the fulfilment of the words of the prophets (cf. Joel 3:1-3) and the annunciation of Jesus (cf. Acts 1:8). To do this he uses biblical images which have already been used for appearances of God in the Old Testament, particularly on Mount Sinai. The rushing of the storm shows the power of the Holy Spirit, who is the breath and the storm of new life. The tongues of fire that come down on every single one of those gathered indicate that the disciples are being enabled and encouraged to witness. The speaking and understanding of foreign languages, together with the list of nations indicates that the world wide mission given to the disciples ends the Babylonian confusion of tongues and shows that the torn human race will be united again. Through mission the nations shall be gathered into a people of God. At Pentecost, the promise is fulfilled and at the end of time, the spirit of God will be poured over all flesh, over big and small, young and old, Jews and Pagans (cf. Joel 3:1-2; Acts 2:17-18; 10: 44-48) […]
Paul, too, knows extraordinary gifts of the Spirit. For him, the emphasis is not on the noticeable phenomena but on daily Christian life. The Spirit is not so much the power of the extraordinary as the power, to do the ordinary in an extraordinary way. He becomes apparent particularly in the commitment to Jesus Christ (cf. 1 Cor 12:3) and in the service for the building up of the community (cf. 1 Cor 13-14). Paul understands the Spirit also as the driving force in the life of every believer. They shall not be led by the flesh but by the Spirit (cf. Gal 5:16-17; Rom 8:12-13) and bring about the fruits of the Spirit: But the fruit of the Spirit is love, joy, peace, patience, kindness, goodness, faithfulness, gentleness and self-control (Gal 5:22-23). Thus the Spirit effects a twofold openness in people: The openness of a person to God, which manifests itself particularly in prayer (cf. Gal 4:6; Rom 8:5-16, 26-27), as well as the openness towards our neighbour. Because the selfless service of love is the true Christian freedom (cf. Gal 5:13). This already hints at the liberation of creation from its impermanence and servitude, for which it waits and hopes. The Spirit is the first gift that gives Christian hope a solid foundation (cf. Rom 8:18-27)”. Katholischer Erwachsenen-Katechismus (The Catholic Catechism, The Creed of the Church. Editor the German Bishops Conference 1985), p. 222-224.