This Sunday (May 19) is the Christian holiday known as Pentecost, widely regarded by many believers as marking the actual birth or nativity of the church.

Pentecost commemorates the descent of, and the manifestation among Christ’s apostles, of the Holy Spirit (one of the three divine Persons of the holy Trinity, which along with the Father and the Son together comprise the triune God of Christianity).

The term pentecost is Greek for “fiftieth,” and signifies the fact that this particular holy day falls upon the fiftieth day following Easter Sunday, the holiday celebrating Christ’s resurrection (with Easter itself counting as “day one” of the fifty-day countdown). Like Easter, Pentecost is also always on a Sunday.

According to the New Testament book known as Acts of the Apostles, it was while celebrating the Jewish holiday of Shavuot that a number of Christ’s disciples suddenly and vividly experienced the indwelling presence of the Holy Spirit.

One outward manifestation of this “baptism of the Holy Spirit” (as it came to be known) was the phenomenon of glossolalia, or “speaking in tongues.” According to Acts, this particular “gift of the Spirit” resulted in the disciples spontaneously and miraculously preaching the gospel in a variety of diverse foreign languages.

Today, this phenomenon or practice of glossolalia remains linked with the modern Pentecostal movement, current since the early 20th century within contemporary evangelical Christianity.

Different Christian denominations place varying degrees of emphasis upon observing Pentecost. For some, it is celebrated as a major feast day; for others, it receives less attention than other major Christian holidays (and some seem to virtually ignore it).