It would be highest number of visitors the occasion has garnered in decades. The annual Katholikentag celebration, known as the German Catholic Convention in English, which turns 101 on Wednesday, is expecting more than 50,000 participants. Not only is this the biggest showing in 30 years, there are also several high profile names on the guest list, including Chancellor Angela Merkel and members of her cabinet.

Despite these record-breaking numbers, a divisive debate has been circling around the festival's 1,000 individual events for weeks. The Central Committee of German Catholics (ZdK) has as one of its members Volker Münz, an MP in the national parliament from the right-wing Alternative for Germany (AfD), who has been invited to speak at an event concerning the relationship between church and state.

Although a representative from each party in parliament is expected to speak, the participation of an AfD nationalist has sowed the seeds of controversy.

In 2016, the ZdK was criticized for intentionally neglecting to invite any of the right-wing populists to that year's celebration in Leipzig. Yet their inclusion this year seems to have prompted criticism as well, particularly from church youth organizations.

Though protesters follow the AfD wherever they go, nowhere has this perhaps been more apparent than in the university city of Münster. It was here in February 2017 where some 8,000 took to the streets to peacefully demonstrate against the party's New Years' meeting at the city's historic town hall.

Playing the victim

"The members of every party responsible for religious policy" were invited, ZdK President Thomas Sternberg told public broadcaster WDR. He said that included "unfortunately, by God," the AfD.

"If we had refused to extend an invitation to one of the parties in the Bundestag, then the AfD would have called themselves victims," he said, "and then there would have been an uproar of no small proportions."

The publicist Andreas Püttmann, who has long dealt with the relationship between the church and the AfD, agrees. He said the church should indeed stand up for victims, for people being persecuted, but he disputes whether the AfD belongs in that category. 

"The church is no talk show and shouldn't function as part of a political debate about integration," said Püttmann, author of the book "How Catholic is Germany," referring to the AfD's anti-immigration stance. "If taboo breakers like this are allowed on Catholic podiums, this could contribute to the fracturing of the Christian ethos. In this case it would have been better for the church to clearly draw a line against this."

"Seek Peace" is the motto of this Christian gathering; a reference to the 30 Years' War, which began exactly 400 years ago. The bloody religious conflict killed millions of people across Europe and only ended when the Peace of Westphalia agreement was signed — in Münster — in 1648.

The current state of the world and the decisive course of Pope Francis gives this historical slogan a link to the present. On that count, one of this year's participants is Colombian President Juan Manuel Santos, who was given the Nobel Peace Prize after his administration negotiated the end of a decades-long civil conflict in his country. Indeed, this year's festival has quite a high concentration of politicians: German President Frank-Walter Steinmeier, Chancellor Merkel, nine cabinet members, the heads of government from three German states, and several party leaders.

After an attack

The question of conflict and violence took on a tragic dimension in Münster last month, one that will surely leave a mark on this year's German Catholic Convention. On April 7, a reportedly mentally ill man drove a vehicle into a street cafe, killing three and injuring many others before shooting himself — sending panic across Germany about a possible terror attack. As a result, organizers of the event have worked hard on increased security. Many streets in downtown Münster will remain completely closed until Sunday.

An especially interesting part of the celebration will no doubt be a discussion of anti-Semitism, a last-minute addition to the program.

There is also another conflict among German bishops that has been heating up in recent weeks — whether or not Protestant spouses of Catholics should be allowed to take communion. As if the Church has no other problems.