Pentecost, the feast on which the Holy Spirit descended like tongues of fire upon the Holy Apostles and other disciples of our Lord in the Upper Room is celebrated on June 12. In the Book of Acts is said, “When the Day of Pentecost had fully come; they were all with one accord in one place. And suddenly there came a sound from heaven, as of a rushing mighty wind, and it filled the whole house where they were sitting.
Then there appeared to them divided tongues, as of fire, and one sat upon each of them. And they were all filled with the Holy Spirit and began to speak with other tongues, as the Spirit gave them utterance.” (Acts 2:1-4)