On the feast of Pentecost, the Holy Spirit did indeed come down in an extraordinary way on the apostles as they were gathered together with Mary, the mother of Jesus, and the group of disciples. They were “so filled with” the Holy Spirit (Acts 2:4) that by divine inspiration they began to proclaim “the mighty works of God.”
In the sacrament of confirmation the apostles and the bishops, who are their successors, hand on to the baptized the special gift of the Holy Spirit, promised by Christ the Lord and poured out upon the apostles at Pentecost. Thus the initiation in the Christian life is completed so that believers are strengthened by power from heaven, made true witnesses of Christ in word and deed, and bound more closely to the Church.
The Sacrament of Confirmation is conferred through the anointing with chrism on the forehead, which is done by the laying on of the hand, and through the words: “Be Sealed with the Gift of the Holy Spirit.”