Martin Luther understood the power of social media to shake and shape the world.

On Oct. 31, 1517, the German monk, scholar, and hymnodist is said to have posted his incendiary thoughts about the Roman Catholic Church on the Facebook of his day: the door of the Castle Church in Wittenberg, in what is now Germany, which was drawing especially heavy traffic on the eve of All Saints' Day.

Luther's "Disputation on the Power and Efficacy of Indulgences," known as the "95 Theses," went viral. His multitude of grievances against the Vatican, from its concept of salvation to its sale of God's forgiveness, spread throughout Europe, leading to a splintering of the faithful and the birth of modern Protestantism.

Five hundred years later, believers are marking the anniversary of the start of the Protestant Reformation in ways sacred, sweet, and sudsy.

The observances officially began on Oct. 31, 2016, when Pope Francis and Bishop Munib A. Younan of the Lutheran World Federation met in Sweden to affirm the two Christian traditions' ecumenical efforts. Locally, the Luther hoopla is focused on this weekend, with special church services, museum tours, theatrical productions, parties, and trivia games. Online websites are selling Martin Luther bobblehead dolls and bonbons. St. Andrew's Evangelical Lutheran Church in Perkasie is hosting a Lutherfest on Saturday with a "Mighty Fortress cakewalk," named for the hymn by Luther. And the Iron Hill Brewery in Phoenixville has created a beer called "Heavenly Indulgence" in honor of the theologian's reputed thirst.

Jay Poff sings during a rehearsal of “Luther,” a modern musical retelling of the heresy trial of theologian Martin Luther to be performed at the Church of the Saviour in Wayne on Sunday.
STEVEN M. FALK / Staff Photographer
Jay Poff sings during a rehearsal of “Luther,” a modern musical retelling of the heresy trial of theologian Martin Luther to be performed at the Church of the Saviour in Wayne on Sunday.

At 3 p.m. Sunday at the Philadelphia Episcopal Cathedral, clerics and laity of Catholic and Protestant churches will be "Celebrating One Baptism in Christ," a Reformation observance to encourage cooperation among faith traditions.

"This isn't just navel-gazing on the part of Christians, but Christians making a statement," said Norman Hjelm, a board member of the Philadelphia Liturgical Institute, an ecumenical group that is sponsoring the service. A struggling religion with plunging membership rolls should offer a clear and compelling message to "a world that needs community."

The service's homilies will be delivered by the Rev. Gordon Lathrop, professor emeritus from the former Lutheran Theological Seminary of Philadelphia, now United Lutheran Seminary, and the Rev. G. Dennis Gill, director of the Archdiocese of Philadelphia's Office for Divine Worship and rector of the Cathedral Basilica of SS. Peter and Paul.

Gill does not refer to the service as a "celebration" of the Reformation, he said, because the schism in Christianity is "a wound that we are trying to deal with in a careful way."

Any Luther observance, scholars add, must not ignore the monk's later writings, which displayed his intolerance toward any faith but Christianity. They were fraught with anti-Jewish sentiments and disparaging of Islam, as he worried about the power of the Ottoman Turks. Lutheran denominations worldwide have repudiated those writings and taken part in Lutheran-Muslim dialogues.

A Lutheran-Catholic dialogue has been ongoing since the Second Vatican Council (1962-65) in an effort to heal centuries of acrimony.

"For a long time, Roman Catholic kids grew up learning Martin Luther was a heretic," Lathrop said, "and Lutheran kids grew up thinking Catholics weren't really Christians, both massive distortions."

A marriage between a Catholic and a Lutheran used to cause serious family discord, said the Rev. Philip D.W. Krey, former president of the seminary and pastor of St. Andrew's in Perkasie.

"When I was a kid, you didn't think of going into a Presbyterian, Lutheran, or Methodist church. It was unheard of, " said the Rev. Peter Donohue, president of the Catholic Villanova University and an Augustianian, like Luther.

In 1999, the Catholic Church (by pontifical council) and the Lutheran World Federation collaborated on the "Joint Declaration on the Doctrine of Justification" — the subject of one of Luther's primary criticisms of Catholicism. He believed that salvation and forgiveness came by way of grace through faith alone. Catholic doctrine held that both faith and good works would gain God's favor. The agreement acknowledged Luther's position, but allowed for a variety of interpretations of "justification by God's grace through faith in Christ." Other Protestant bodies, including the World Methodist Council and World Communion of Reformed Churches, also signed the document.

Luther never intended to break from Catholicism, Donohue said. He wanted the church to consider whether its policies reflected the gospels' values.  He took action only after a papal representative visited German-speaking lands to sell indulgences — remission from penance for committing a sin — in order to raise money to build St. Peter's Basilica in Rome. The church was essentially putting God's forgiveness for sale.

"They preach vanity who say that the soul flies out of Purgatory as soon as the money thrown into the chest rattles," Luther wrote. "What is sure, is that as soon as the penny rattles in the chest, gain and avarice are on the way of increase; but the intercession of the church depends only on the will of God himself."

His writings espoused a "modern and almost postmodern" message about equality and faith, said the Rev. Kirsi I. Stjerna, a historian, professor at Pacific Lutheran Theological Seminary in Berkeley, Calif., and author of Women and the Reformation.

"That none of us is better than the other in the eyes of God — these were radical ideas in his world," she said. "Emancipation was his theology, that every vocation is holy. You don't have to be a nun or pope. You could be a washerwoman, and you are holy."

Such views, and Luther's refusal to renounce them, resulted in his excommunication from the Catholic Church. He later married a former nun, whom he had helped escape from a convent in a herring barrel, and fathered six children with her. He continued to write and lecture, and eventually established what is now the Lutheran Church. He died in 1546 after suffering a stroke.

A cast of 11 and a choir of 150 will dramatize some of the most harrowing days in the life of the theologian on Sunday in Luther, a contemporary musical based on his heresy trial, during which papal representatives tried to force him to recant his beliefs.  The two-hour show, with a score of rock, jazz, folk, and almost-metal will begin at 7 p.m. at the Church of the Saviour in Wayne.

Producer Drew Pulver, an actor and teacher from Lancaster, adapted the work from a production commissioned by the German government to commemorate the Reformation. "The whole concept of the work is to show the issues of the Reformation are still relevant," he said, "and still being worked out today."