The Holy Spirit guides and influences the Church
One way the Holy Spirit guides and influences the Church is through missionary life and in the signs of apostolic life.
"The Church, a communion living in the faith of the apostles which she transmits, is the place where we know the Holy Spirit: in the signs of apostolic and missionary life" (CCC, Article 8, 688.) The Catechism states that the Church is the place where we know the Holy Spirit. The Holy Spirit can be known in the signs of apostolic and missionary life because these events have influenced the Church.
"The promise of the Holy Spirit is the culmination of all that Jesus said to comfort those eleven troubled men. In that hour of turmoil, they feared being left alone. However Jesus assured them that they would not be left to fend for themselves; they would have a supernatural Helper"(9marks.org.) Just as the apostles had the comfort from the Holy Spirit in their hour of turmoil, so will the Church. The Church will not be left alone, but rather have a Helper, the Holy Spirit.
“With the coming of the Holy Spirit on the day of Pentecost, the Holy Trinity was fully revealed. Certainly the Holy Spirit had been at work in the world before this day" (Ave Maria Press.) The Holy Spirit can guide the Church through Pentecost. The Holy Spirit came on that day, and continued to work throughout the Apostles lives.
"5 Then some of the believers who belonged to the party of the Pharisees stood up and said, “The Gentiles must be circumcised and required to keep the l law of Moses.” 6 The apostles and elders met to consider this question. 7 After much discussion, Peter got up and addressed them: “Brothers, you know that some time ago God made a choice among you that the Gentiles might hear from my lips the message of the gospel and believe. 8 God, who knows the heart, showed that he accepted them by giving the Holy Spirit to them, just as he did to us. 9 He did not discriminate between us and them, for he purified their hearts by faith. 10 Now then, why do you try to test God by putting on the necks of Gentiles a yoke that neither we nor our ancestors have been able to bear? 11 No! We believe it is through the grace of our Lord Jesus that we are saved, just as they are" (Acts 15.) Since Christ accepts the Church, the disciples are given the Holy Spirit. The Holy Spirit gives disciples the message of the gospel to help others believe.