What key event does Pentecost commemorate in Christian belief?

Pentecost commemorates the descent of the Holy Spirit on the Apostles, a pivotal event in Christian belief that took place fifty days after Easter, marking the end of the Easter season. This event is significant because it is considered the birth of the Christian Church. According to the New Testament in the Book of Acts, during Pentecost, the Apostles were filled with the Holy Spirit and began to speak in different languages, enabling them to communicate with a diverse audience gathered in Jerusalem for the festival. This miraculous event empowered the Apostles to spread the message of Jesus Christ effectively, leading to the conversion of many individuals and the rapid growth of the early Church.

The other options reflect important aspects of Christian faith but do not encapsulate the core significance of Pentecost. The creation of the world and the teaching of Jesus are vital elements of Christian doctrine but occur at different points in the timeline of biblical history. The establishment of the church hierarchy relates to organizational developments in the Church but is not what Pentecost is primarily about. Thus, the descent of the Holy Spirit is central to understanding why Pentecost is celebrated by Christians around the world.