From the OCIC: A Special Message for the Period from Ascension to Pentecost
"Beloved brother, after the recently celebrated Feast of the Ascension of the Lord, after the joy of Christ's Resurrection, now that the path of asceticism has opened up also for you, you should likewise continue in prayer in anticipation of that great and crowning feast of Holy Pentecost. Of course, ever since that first Pentecost in the time of the holy Apostles, the Holy Spirit has continuously and consistently been and ever will be in the Church, and His grace, without ever diminishing, performs all the Mysteries through the course of the year. But know that on the Feast of Holy Pentecost, when the Holy Church triumphantly celebrates the outpouring of the Holy Spirit upon the Church, this is not only a remembrance of a past eventeven though this particular event in time was of great significance both for the past and for the present and for the future (all feasts and mysteries celebrated by the Church possess significance for the future)but this is also a special and most abundant outpouring of the Holy Spirit in the Church, when His grace is signed most powerfully upon all those who on that day come to church with prayer, and, bending their hearts and knees, pray to receive the Holy Spirit into their souls and a blessing upon their lives.
"The holy Apostles, as we said, continued in prayer and supplication, awaiting the descent of the Holy Spirit. So likewise do you, following their example, pray in advance and with fervent prayer prepare yourself in such a way that the grace of the Holy Spirit not only touch you but that it come to abide constantly in your heart. Do not think that the time between Ascension and Pentecost is some kind of empty space. No, this time is given to us with a purpose, that we might prepare ourselves to receive a great gift and mystery. Further, it does not say in Scripture that, awaiting the descent of the Holy Spirit, the Apostles continued in prayer and fasting, as they did on other occasions (Acts 13:3; 14:23; I Cor. 7:5; II Cor. 6:5, 11:27). It says simply that they continued in prayer and supplication, and that their waiting for this great gift (Acts 11:20) was not joined with any labors or difficulties; their ascesis in this case was only spiritual. The descent of the Holy Spirit was the beginning of a New age, the foretaste of a blessed life in heaven, where there will be rewards for ascetic labors but not the labors themselves; it will be a time of rest and tranquility, not labors and battles... And of you is required, now, no fasting or prostrations, but only the joyous anticipation of grace and an abiding in prayer. Take care that you are not negligent in this regard. Like Christ's holy disciples in ancient times, so too, you, who are also Christ's disciple, remain in church, praising and blessing God (Luke 24:53).
"And so, after the Lord's Ascension in the flesh and until Pentecost, the holy Apostles awaited the coming of the Holy Spirit. Because the Holy Spirit had not yet descended, the Church had not yet received that invaluable, precious gift. The Body of the Church was still soulless, inanimated, as it were. The Holy Spirit had not yet come to give life to and to animate the Church of Christ; the heart of the Church had not yet begun to beat.
"O Holy Spirit, come and enter into the heart of the Church of the Son of God! O Holy Spirit, come also into our earthly temples and into our hearts! Yes, brother, the Holy Spirit will come into God's temples. Take care that He likewise come into your soul and body. You know that the Church is there where the Holy Spirit dwells; without the Holy Spirit there is no Church. For this reason heretical assemblies cannot be called the Church, even though their external form might resemble the Church. Know that this is merely a corpse without life. The Holy Spirit is there where there is correct faith and unyielding confirmation in virtue and truth. It is about such a Church that the Lord testifies as of His Bride, addressing her prophetically: Thou art all fair, My companion, and there is no spot in thee (Song of Solomon 4:7)." (From Reflections of a Humble Heart, pp. 33-35)