Baptism is “the doorway to the spiritual life; it makes us members of Christ and draws us into the body of the Church.”
Ecumenical Council of Florence -1439

“In confirmation the baptized “are joined more completely to the Church; they are enriched with special strength by the Holy Spirit and thus are more solemnly obliged to spread and defend the faith in word and deed as true witnesses of Christ.”
Second Vatican Ecumenical Council, Dogmatic Constitution on the Church, Lumen Gentium — 1964
But, how do we come to know the Spirit?
From the Catechism of the Catholic Church:
687 “No one comprehends the thoughts of God except the Spirit of God.”7 Now God’s Spirit, who reveals God, makes known to us Christ, his Word, his living Utterance, but the Spirit does not speak of himself. The Spirit who “has spoken through the prophets” makes us hear the Father’s Word, but we do not hear the Spirit himself. We know him only in the movement by which he reveals the Word to us and disposes us to welcome him in faith. The Spirit of truth who “unveils” Christ to us “will not speak on his own.”8 Such properly divine self-effacement explains why “the world cannot receive [him], because it neither sees him nor knows him,” while those who believe in Christ know the Spirit because he dwells with them.9
688 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 Scriptures he inspired;
– in the Tradition, to which the Church Fathers are always timely witnesses;
– in the Church’s Magisterium, which he assists;
– in the sacramental liturgy, through its words and symbols, in which the Holy Spirit puts us into communion with Christ;
– in prayer, wherein he intercedes for us;
– in the charisms and ministries by which the Church is built up;
– in the signs of apostolic and missionary life;
– in the witness of saints through whom he manifests his holiness and continues the work of salvation.
Prayers and Holy Mass this day for all Christian youth preparing for confirmation in the Spirit, and their teachers.