The Holy Spirit enables us as Christians to become fruitful members of the Body of Christ, which is the Church. The mystical Body of Christ that St. Paul writes about in Scripture consists of the Old Testament and New Testament Saints in Heaven as well as the baptized Christian followers of Our Lord here on earth, the Church. As St. Paul notes, we, the Church, are surrounded by a cloud of witnesses in Heaven (Heb 11). The Holy Spirit dwelling within us can and does transform our lives, the Church and the world. St. Paul also urges that, “We live by the Spirit.” We do this when we renounce ourselves, the more we “walk by the Spirit.” (Gal 5:25). This power is not confined to the sacraments. There is an experience sometimes referred to as the “Baptism of the Holy Spirit.”
As St. Thomas Aquinas notes the Holy Spirit can be given or sent to us to indwell us and “make us new.” This begins at our Baptism, but the Spirit can be given or sent after this according to St. Thomas, who wrote, “The is an invisible sending [of the Holy Spirit] also in respect to an advance in virtue or an increase of grace . . . Such an invisible sending is especially to be seen in that kind of increase of grace whereby a person moves forward to some new act or new state of grace: as, for instance, when a person moves forward into the grace of working miracles, or of prophecy or out of the burning love of God offers his life as a martyr, or renounces all of his possessions, or undertakes some other such arduous thing.”
Christ’s promise of another Paraclete, an Advocate, was fulfilled on Pentecost for the Apostles and Mary, who had been praying fervently for nine days. This extra measure of the Spirit seems to have been conferred in other places in the Acts of the Apostles (e.g., Acts 4:31; 19:1-7). The Holy Spirit then can “make us new” when we surrender to God and serve Him with our whole heart, thus aiding our personal holiness (without which no man can see God) and the work of the Church. This, however, does not take the place of sacramental Baptism or Confirmation, but rather is a way of opening ourselves up further to the life in the Spirit. This may be experienced by an overwhelming sense of the presence and love of God, or a sense of being filled with joy and peace. In Scripture, we see it was accompanied at times by the gift of speaking in tongues. As the Catechism says, “The moral life of Christians is sustained by the gifts of the Holy Spirit” which make us more willing to be led by the Spirit. St. Paul wrote, “For all who are led by the Spirit of God are sons of God . . . If children, then heirs, heirs with God and fellow heirs with Christ” (Rom 8:14, 17).