What's Pentecost Sunday?

Pentecost Sunday falls on May 24 this year (2015) and it is generally honored in liturgical churches (Roman Catholic, Anglican, Lutheran, Eastern Orthodox, etc.), and in many other Protestant churches as well. Pentecost is not as well-known or as popular as the Christmas and Easter, though it commemorates a watershed event in Christian history.

But many Christians don't know why the day is special or what is celebrated. 

Unlike Easter and Christmas, when colorful eggs, Easter bunnies, Christmas trees and Santa Claus are harbingers of the upcoming Christian holidays, there are no such social/secular markers for The Day of Pentecost. So, for those who need a quick and basic understanding of what Pentecost Sunday is, we have listed 10 things you should know about the Christian observance of Pentecostal Sunday.

1. Pentecost Sunday marks the day when the Holy Spirit descended upon the Apostles.
2. Pentecost Sunday occurs 50 days after Easter/Resurrection Sunday.
3. The Bible records the Day of Pentecost in Acts 2:1-13.
4. The Day of Pentecost came 10 days after the Ascension of Jesus Christ.
5. The Day of Pentecost is also known as "the birthday of the Church".
6. Pentecost fulfills Jesus' promise to send the "Counselor" and "Spirit of Truth" in John 16-5-15.
7. Pentecost launches the large-scale spreading of the Gospel after Jesus' ascension. Acts 2:41 records that after Peter spoke to the crowd after receiving the Holy Spirit, some 3,000 people were baptized.
8. Pentecost Sunday is not linked with the Pentecostal movement. (In fact, many Pentecostal churches make little to no fuss over Pentecost Sunday.)
9. Jews also celebrate Pentecost, but not for the same reason as Christians. The celebration by Jews of Pentecost is to observe God giving the Ten Commandments on Mount Sinai 50 days after the Exodus. The Pentecost in Jewish tradition takes place 50 days after Passover.
10. In many mainline Western churches, Pentecost is usually represented with the color red, which symbolizes the fire of the Holy Spirit.