The Holy Spirit recalls the mystery of Christ
The Holy Spirit gives a spiritual understanding of the Word of God to those who read or hear it, according to the dispositions of their hearts. By means of the words, actions, and symbols that form the structure of a celebration, the Spirit puts both the faithful and the ministers into a living relationship with Christ, the Word and Image of the Father, so that they can live out the meaning of what they hear, contemplate, and do in the celebration.
Source: Catechism of the Catholic Church (Vatican.va)