What is Pentecost Sunday and why do churches mark it?

Pentecost is commonly called the birthday of the Church but why is that? This is the story …

Pentecost

Pentecost Sunday is certainly one of movable feasts within the Church calendar. This is since it relies on the date of Easter. In the Church calendar it falls seven Sundays or 50 days after Easter Sunday. 

Pentecost commemorates the approaching of the Holy Spirit on Jesus’s disciples. This happened just after his Ascension on the Feast of Pentecost. The event is recorded in the primary two chapters of the Acts of the Apostles, which was written by Luke. It isn’t absolutely sure which yr this happened, but most scholars as of late think it was AD 33. Others think it was AD 28, 29 or 30.

Origin of the Word

The word ‘Pentecost’ comes from the Greek term for the Jewish holiday of Shavuot. In the Jewish calendar Passover was followed by Shavuot, which was called the Feast of Weeks, and it was the Harvest Festival which celebrated the primary fruits of the wheat harvest within the Holy Land.  

In Hebrew the words ‘seven’ and ‘week’ are related. The Feast of Weeks was ‘per week of weeks’ or seven weeks.  Every week of weeks is 49 days.  The Sabbath following per week of weeks is the fiftieth day.  The instructions for this within the Bible read: “Count seven full weeks from the day after the Sabbath on which you bring your sheaf of corn to present to the LORD. On the fiftieth day, the day after the seventh Sabbath, present to the LORD one other recent offering of corn” (Leviticus 23:15-16, GNB). The New Testament was written in Greek and the Greek for ‘fiftieth’ is Πεντηκοστή  (Pentēkostē), hence Pentecost. 

What happened?

At Pentecost the Holy Spirit descended upon the disciples.  Peter stood up and preached telling the story of Jesus to the crowds. That Harvest Festival was the primary fruits of the nice harvest of souls. About three thousand people joined the Church at Pentecost (Acts 2:41).  These people were Jews of the Diaspora, and a few Gentile converts to Judaism. They returned to their homelands and synagogues with the Gospel message. 

According to the list in Acts 2:Sept. 11, the people returned to their places of origin in what are today called Greece and Italy in Europe; the Holy Land, Turkey, Iraq, Iran, Arabia within the Middle East; in addition to Egypt and Libya in north Africa.  Sometimes Jews also come from a bit further afield as well.  A bit later we also read in Acts 8:27 of the Ethiopian eunuch who got here to Jerusalem to worship. In fact these are the geographical areas where the Early Church was strongest.

St Paul and Pentecost

The word ‘Pentecost’ is found only 3 times in English versions of the Bible. It is present in Acts 2:1, which is the date when the Holy Spirit got here down. Pentecost seems to have been a very important festival for St Paul. We read in Acts 20:16 that St Paul tried to get from Ephesus to Jerusalem for Pentecost, and he wrote in 1 Corinthians 16:8 that he desired to stay in Ephesus for Pentecost. 

Date of Pentecost

Eastern and Western Easter Sundays fall on different dates most years, and due to this fact Pentecost, which is seven Sundays later, also falls on different dates. But in 2025, Easter Sunday and Pentecost Sunday fall on the identical date for Orthodox, Catholic and Protestant Christians.

Whitsun

In the UK, Pentecost Sunday was traditionally generally known as Whitsunday, and the period was generally known as Whitsun. This word comes from the term White Sunday, because historically people wore white gowns for baptism on Pentecost, which remains to be the tradition in some countries. The day after Pentecost Sunday was called Whit Monday.   

Birth day or Birthday?

Sometimes there may be some confusion over whether Pentecost was the birth day (two words) or the birthday (one word) of the Church. In English we are saying that the day you were born is the day of your birth, and subsequent anniversaries of your birth are your birthdays. A yr after you might be born you may have your first birthday. Christians often see Pentecost as the beginning of the Church. It is when the Church was birthed, and so the unique first Pentecost recorded in Acts 1-2 was the day of birth (birth day) of the Church, and subsequent anniversaries of it are its birthday.