On June 19, the Orthodox Church will commemorate a great event in human history – the descent of the Holy Spirit upon the Apostles, an event the Church celebrates on the day of the Holy Trinity (Pentecost).

The tenth day following the Ascension of our Lord Jesus Christ was the fiftieth day following Christ’s Resurrection. Following the Lord’s direct instruction, all of the Apostles, the Mother of God, other disciples of Christ, and other faithful were together, of one accord, in Jerusalem. It was the third hour of the day – in our terms, 9:00 AM. Suddenly there was a sound from the Heavens, like unto a mighty rushing wind, filling the entire house in which Christ’s disciples were. Then, tongues of fire appeared and came to rest upon, i.e. as it were became established upon, each of them, a single tongue of fire upon each. This is the manner in which that great event is depicted upon icons of the Feast of the Holy Trinity – the assembled Apostles and the Mother of God, their eyes gazing up to Heaven, and symbols of the Divine Fire above their heads.

All of those assembled in the Upper Room in Jerusalem were filled with the Holy Spirit and began to praise God in various tongues hitherto unknown to them. Thus, as promised by the Savior, the Holy Spirit descended upon the Apostles, in the form of tongues of fire, in token of the fact that the Holy Spirit had given the Apostles the ability and power to preach Christ’s teachings to all nations. It descended in the form of fire in token of the fact that it had the power to burn up sins and to cleanse, to sanctify, and to comfort and inspire the soul.

On the occasion of the Pentecost, there were at that time many people in Jerusalem who had come from various foreign countries; of course they were conversant in the languages of those countries. Hearing the noise, an enormous crowd gathered near the house in which Christ’s disciples were. Everyone in the crowd was astounded and asked one another, “…are not all these which speak Galileans? And how hear we every man in    our own tongue, wherein we were born? How do we “... hear them speak in our tongues the wonderful works of God?” Many of them suggested that the disciples were drunk.

Then the Apostle Peter, standing up with the eleven disciples, said that they were not intoxicated, but that, as prophesied by the Prophet Joel, the Holy Spirit had descended upon them, and that Jesus Christ, Whom the Jews had crucified, had risen from the dead, ascended into Heaven, and poured out the Holy Spirit upon them. Concluding his homily on Jesus Christ, the Apostle Peter said, “Let all the house of Israel know assuredly, that God hath made that same Jesus, whom ye have crucified, both Lord and Christ.” (Acts 2: 36)”

Peter’s preaching so affected his listeners that quite a multitude came to believe on Jesus Christ. They began to ask Peter and the other Apostles, “Men and brethren, what shall we do?” Peter answered, “Repent, and be baptized every one of you in the name of Jesus Christ for the remission of sins, and ye shall receive the gift of the Holy Ghost.” (Acts 2:38) Those who believed on Christ eagerly received Holy Baptism; that day, their number was about three thousand. In this manner, the Holy Church of Christ began to become established on earth.

Preceding the Feast of the Holy Trinity is a special commemoration of the departed – Holy Trinity Ancestral Saturday (18 June).

Thus, three Feast Days – Holy Trinity Ancestral Saturday, the Feast of the Holy Trinity, and the Day of the Holy Spirit (the Monday following Pentecost) are days of intensified prayer both for the living and the dead, days of commemoration and salvation for all of us. That is why it is so important on those days to be together with our children, our entire families, in the Church of God, so that we might be one in prayer and in the sure hope of acquiring true treasure, the grace of the Holy Spirit, that was given first to the Apostles, and then to all of us Orthodox people. According to St. John Chrysostom, the Holy Spirit comes to us during prayer. Prayer is a means always available to us, but it is especially important to put it to use on Feast Days.

On Trinity Sunday, it is customary to decorate churches and homes with tree branches, grass and flowers. That is how the Old Testament Church celebrated Pentecost, and in all probability, it was how the upper room on Mt. Zion was decorated on that blessed day. The custom may also have been influenced by the appearance, in the form of three strangers, of God to Abraham at the Oak of Mamre, the site of the patriarch’s tent.

The New Testament Church retained that custom, but gave it a new meaning: Now the young greenery and flowers symbolize not only the bringing to God of the first fruits of the renewing Spring season, but also the Church of Christ itself, the Church which had, as it says in the liturgical chant, blossomed like a flower; likewise, it symbolizes people’s renewal by the Holy Spirit.