Who Is the Holy Spirit?
The Holy Spirit is the third Person of the Holy Trinity — not a force, not an energy, not a divine influence, but a Person: fully God, co-equal and co-eternal with the Father and the Son. The Nicene Creed confesses: "I believe in the Holy Spirit, the Lord, the Giver of Life, who proceeds from the Father, who together with the Father and the Son is worshipped and glorified, who spoke through the Prophets."
The Spirit is the breath of God (the word pneuma means both spirit and breath), hovering over the waters at creation (Genesis 1:2), inspiring the Prophets, descending upon Mary at the Annunciation, resting upon Christ at His Baptism. He is the divine Person who makes the absent Christ present within the Church — who makes the bread and wine truly the Body and Blood of Christ, who seals the newly baptized with the sign of the Kingdom, who prays within us when we do not know how to pray.
"Prayer is the work of the Holy Spirit in us. When we pray, we are not reaching upward to a distant God — we are responding to a divine Person already dwelling within us, already interceding on our behalf."
Pentecost: The Birth of the Church
Fifty days after Pascha, the disciples were gathered in Jerusalem when suddenly there came a sound from heaven like a rushing mighty wind, and tongues of fire appeared and rested on each of them. They were filled with the Holy Spirit and began to speak in other languages (Acts 2:1-4). This was the promised coming of the Comforter whom Christ had promised: "I will ask the Father, and He will give you another Helper, to be with you forever" (John 14:16).
Pentecost is the birthday of the Church. Before Pentecost, the disciples were fearful, confused, and scattered. After Pentecost, they proclaimed the Resurrection boldly throughout the world, founding communities everywhere they went, establishing the Church that has continued unbroken to this day. Every time the Church gathers to pray, every time the Eucharist is celebrated, every time a soul is baptized — Pentecost continues.
The Spirit in the Life of the Believer
At Chrismation (Confirmation), every Orthodox Christian receives the gift of the Holy Spirit personally — the seal and anointing that makes each believer a temple of God (1 Corinthians 6:19). The great task of the Christian life, according to Saint Seraphim of Sarov, is precisely "the acquisition of the Holy Spirit." Prayer, fasting, and the sacraments are not the goal — they are the means by which the Spirit is invited to work more and more deeply within the soul.
The goal of Christian life is the acquisition of the Holy Spirit of God. As for fasting, vigil, prayer, almsgiving, and every good deed done for Christ's sake — these are only means for acquiring the Holy Spirit.
— St. Seraphim of Sarov