Final answer:
The Holy Spirit was given to the Church during the occasion of Pentecost, which occurs fifty days after Easter.
Step-by-step explanation:
The Holy Spirit was given to the Church on the occasion of Pentecost, which is commemorated fifty days after Easter, known as Pascha. This event, depicted in Acts 2, describes the descending of the Holy Spirit in the form of tongues of fire upon the Apostles and is a cornerstone of Christian doctrine. In the vivid description, the Apostles are inspired to speak in different languages, which allows people of various tribes and tongues to understand the message of the crucified and risen Christ. The observance of Pentecost holds immense significance in Christian tradition, marking the moment when the Church was endowed with the Holy Spirit, empowering the Apostles to spread the teachings of Jesus Christ.