Tongue Tied: Pentecost — a holiday once celebrated on a scale rivaling Christmas or Easter — has faded into obscurity outside of Europe. Could it stage a comeback?

In the United States, this Memorial Day weekend will be devoted to backyard barbeques welcoming summer, and parades in remembrance of fallen soldiers. But in much of Europe and a few parts of Africa and the Caribbean, Monday will be a public holiday for a very different reason: These countries will be taking the day off for Pentecost, a Christian celebration with a history of observance nearly as rich as Christmas or Easter, but that today has faded to relative obscurity outside of the church itself.

Pentecost Sunday, which takes place 50 days after Easter, commemorates an event recounted in the Book of Acts: the descent of the Holy Spirit, amid “cloven tongues like as of fire,” upon the early followers of Jesus in Jerusalem. Amid “a rushing mighty wind,” the Bible recounts, the devotees “were filled with the Holy Spirit, and began to speak with other tongues, as the Spirit gave them utterance.” They could suddenly speak every language of the diverse crowd assembled. Some onlookers assumed the men were drunk, but were convinced otherwise by a rousing sermon from the apostle Peter. The display prompted thousands to join the church, which many Christians believe was born in that moment.

Nearly 2,000 years later, Catholic, Eastern Orthodox, and many Protestant churches celebrate these biblical events as a major occasion on the liturgical calendar, and in a number of countries, with a public holiday the following Monday — a popular time, historically, for baptisms, feasts, and pilgrimages. For much of Christian European history, the holiday was tied to a host of traditions, including processions, the planting of Pentecost trees, decorating the home with wreathes, and elaborate church services. In Sir Thomas Malory’s 15th century collection of King Arthur tales, Le Morte d’Arthur, the court at Camelot held a high feast on the holiday every year, during which the Knights of the Round Table would reaffirm the Pentecostal Oath — a pledge of commitment to chivalry, resworn yearly.

The Eastern Orthodox Church still observes Pentecost with an all-night vigil: a service called the Kneeling Vespers, involving full prostration, with worshipers touching their foreheads to the floor. The Eastern and Western celebrations of Pentecost often fall on different Sundays, because the liturgical calendars do not align. In the West, Catholic and many Protestant churches mark Pentecost through celebrations that often include red banners and vestments symbolizing the Holy Spirit — staid observances that don’t bear much resemblance the wild furor of the event described in scripture.

The role of the church in European societies has long been on the decline, but the tradition of a public holiday for Pentecost largely persists. Celebrants use their Mondays off to see friends and family, and in some countries, including Estonia and Finland, they decorate eggs — a tradition associated elsewhere with Easter. France tried to get rid of Pentecost Monday in 2005, but the country’s main unions went on strike and 35 percent of the workforce refused to give up their day off, which was reinstated. The U.K. celebrated Pentecost with a public holiday called Whit Monday until 1971, which was replaced by an entirely secular “spring bank holiday” at the end of May.

But as Europe falls away from its historical position at the center of the Christian world, and as evangelicals and Pentecostals expand their share of the overall Christian population, the future of the holiday has come into question. In the Pentecostal tradition — which bears the holiday’s name and is growing rapidly, gaining membership at the expense of the Catholic Church — the holiday often passes without much acknowledgment at all.

Most who celebrate the holiday do so by solemnly commemorating the encounter between early Christians and the Holy Spirit. But charismatic and Pentecostal Christians, in their daily religious practice, seek personal encounters with Holy Spirit similar to what transpired in the Book of Acts: that is, speaking in tongues, divine healing, and an immersion in the divine. For Pentecostals, speaking in tongues is less a linguistic miracle relegated to the biblical past than an ecstatic outpouring of vocalizations, known as glossolalia, during ordinary worship. Pentecost Sunday has no strong hold among the ranks of this growing demographic. Why? For worshippers who experience “gifts of the Sprit” during prayer, that the Holy Spirit once paid a visit to the apostles on Earth isn’t cause for a holiday — it’s the foundation for a whole way of life.

Across the globe, Pentecostalism is on the rise, especially in Latin America and sub-Saharan Africa, according to studies by the Pew Research Center. Future Christians will be less likely than their predecessors to attend a Catholic church or observe the liturgical holidays like Pentecost, but more likely to belong to a Pentecostal church like Assemblies of God, which has seen 24 consecutive years of growth in 190 countries and has become one of the largest denomination overall, with some 67,512,302 adherents.

But Pentecost may have a place in the Pentecostal future: Denominational leaders are starting to encourage observance of the holiday, and congregants who come to Pentecostalism from other churches bring traditions along with them.

Alton Garrison, the second highest Assemblies of God official, said that he would like to see Pentecost celebrated more widely in light of the 2,000th anniversary of events described in the Book of Acts, approaching in 2033. He said he saw the day as an entry point to the Pentecostal message.

“We’ve had an emphasis on trying to get ministers to speak on that subject,” he told Foreign Policy. “It’s important to celebrate the day, but more important to celebrate it as a lifestyle. But if the day will help spark the lifestyle, then so be it.”