German President Frank-Walter Steinmeier addresses closing service of the German Protestant Church Congress Kirchentag in Wittenberg, Germany May 28, 2017. REUTERS/Fabrizio Bensch

German President Frank-Walter Steinmeier (L) addresses closing service of the German Protestant Church Congress Kirchentag in Wittenberg, Germany May 28, 2017. REUTERS/Fabrizio Bensch

German President Frank-Walter Steinmeier addresses the closing service of the German Protestant Church Congress Kirchentag in Wittenberg, Germany May 28, 2017. REUTERS/Fabrizio Bensch

People attend the closing service of the German Protestant Church Congress Kirchentag in Wittenberg, Germany May 28, 2017. REUTERS/Fabrizio Bensch

People attend closing service of the German Protestant Church Congress Kirchentag in Wittenberg, Germany May 28, 2017. REUTERS/Fabrizio Bensch

People attend the closing service of the German Protestant Church Congress Kirchentag in Wittenberg, Germany, May 28, 2017. REUTERS/Fabrizio Bensch

People receive the Lord's Supper during the closing service of the German Protestant Church Congress Kirchentag in Wittenberg, Germany May 28, 2017. REUTERS/Fabrizio Bensch

People receive the Lord's Supper during the closing service of the German Protestant Church Congress Kirchentag in Wittenberg, Germany May 28, 2017. REUTERS/Fabrizio Bensch

A crucifix is seen as people attend the closing service of the German Protestant Church Congress Kirchentag in Wittenberg, Germany May 28, 2017. REUTERS/Fabrizio Bensch

A musician performs at the closing service of the German Protestant Church Congress Kirchentag in Wittenberg, Germany May 28, 2017. REUTERS/Fabrizio Bensch

Musicians perform at the closing service of the German Protestant Church Congress Kirchentag in Wittenberg, Germany May 28, 2017. REUTERS/Fabrizio Bensch

People attend closing the service of the German Protestant Church Congress Kirchentag in Wittenberg, Germany May 28, 2017. REUTERS/Fabrizio Bensch

South Africa's Anglican Archbishop of Cape Town Thabo Makgoba attends the closing service of the German Protestant Church Congress Kirchentag in Wittenberg, Germany May 28, 2017. REUTERS/Fabrizio Bensch

People attend the closing service of the German Protestant Church Congress Kirchentag in Wittenberg, Germany May 28, 2017. REUTERS/Fabrizio Bensch

People attend the closing service of the German Protestant Church Congress Kirchentag in Wittenberg, Germany May 28, 2017. REUTERS/Fabrizio Bensch

German President Frank-Walter Steinmeier (2-R) and his wife Elke Buedenbender (3-R) attend the closing service of the German Protestant Church Congress Kirchentag in Wittenberg, Germany May 28, 2017. REUTERS/Fabrizio Bensch

German Interior Minister Thomas de Maiziere (2-L), his wife Martina (L), President Frank-Walter Steinmeier (R) and his wife Elke Buedenbender attend the closing service of the German Protestant Church Congress Kirchentag in Wittenberg, Germany May 28, 2017. REUTERS/Fabrizio Bensch

German President Frank-Walter Steinmeier and his wife Elke Buedenbender attend the closing service of the German Protestant Church Congress Kirchentag in Wittenberg, Germany May 28, 2017. REUTERS/Fabrizio Bensch

People attend the closing service of the German Protestant Church Congress Kirchentag in Wittenberg, Germany May 28, 2017. REUTERS/Fabrizio Bensch

People attend the closing service of the German Protestant Church Congress Kirchentag in Wittenberg, Germany May 28, 2017. REUTERS/Fabrizio Bensch

Security staff and police check bags at the entrance to the closing service of the German Protestant Church Congress Kirchentag in Wittenberg, Germany May 28, 2017. REUTERS/Fabrizio Bensch

People attend closing service of the German Protestant Church Congress Kirchentag in Wittenberg, Germany May 28, 2017. REUTERS/Fabrizio Bensch

People attend closing service of the German Protestant Church Congress Kirchentag in Wittenberg, Germany May 28, 2017. REUTERS/Fabrizio Bensch

People attend closing service of the German Protestant Church Congress Kirchentag in Wittenberg, Germany May 28, 2017. REUTERS/Fabrizio Bensch

People attend closing service of the German Protestant Church Congress Kirchentag in Wittenberg, Germany May 28, 2017. REUTERS/Fabrizio Bensch

People shield themselves against the sun, as they attend the closing service of the German Protestant Church Congress Kirchentag in Wittenberg, Germany May 28, 2017. REUTERS/Fabrizio Bensch

Visitors line up for a blessing the German Protestant church congress Kirchentag in Berlin, Germany May 26, 2017. REUTERS/Axel Schmidt

Visitors attend the German Protestant church congress Kirchentag in Berlin, Germany May 26, 2017. REUTERS/Axel Schmidt

A visitor sits next to a cardboard figure of Sibylle of Cleves at the German Protestant church congress Kirchentag in Berlin, Germany May 26, 2017. REUTERS/Axel Schmidt

German Foreign Minister Sigmar Gabriel faces protest against Rheinmetall plans to build a tank factory in Turkey, during a talk at the German Protestant church congress Kirchentag in Berlin, Germany May 26, 2017. The placard reads: "Rheinmetalls Tank-Deal Kills!". REUTERS/Axel Schmidt

Visitors attend the German Protestant church congress Kirchentag in Berlin, Germany May 26, 2017. REUTERS/Axel Schmidt

Visitors enter a hall to attend church service at the German Protestant church congress Kirchentag in Berlin, Germany May 26, 2017. REUTERS/Axel Schmidt

Visitors attend a church service at the German Protestant church congress Kirchentag in Berlin, Germany May 26, 2017. REUTERS/Axel Schmidt

German Foreign Minister Sigmar Gabriel attends the German Protestant church congress Kirchentag in Berlin, Germany May 26, 2017. REUTERS/Axel Schmidt

German Foreign Minister Sigmar Gabriel attends the German Protestant church congress Kirchentag in Berlin, Germany May 26, 2017. REUTERS/Axel Schmidt

German Foreign Minister Sigmar Gabriel attends the German Protestant church congress Kirchentag in Berlin, Germany May 26, 2017. REUTERS/Axel Schmidt

Sri Mayurapathy Murugan Hindu-Temple is open for visitors during "Long Nights of Religions" as part of the German protestant church congress Kirchentag in Berlin, Germany, May 25, 2017. REUTERS/Axel Schmidt

Hindu devotees and visitors attend "Long Nights of Religions" at Sri Mayurapathy Murugan Hindu-Temple as part of the German protestant church congress Kirchentag in Berlin, Germany, May 25, 2017. REUTERS/Axel Schmidt

Members of the Afro-Brazilian religion Candomble perform a ceremony with visitors during "Long Nights of Religions" as part of the German protestant church congress Kirchentag in Berlin, Germany,May 25, 2017. REUTERS/Axel Schmidt

Hindu devotees and visitors attend "Long Nights of Religions" at Sri Mayurapathy Murugan Hindu-Temple as part of the German protestant church congress Kirchentag in Berlin, Germany, May 25, 2017. REUTERS/Axel Schmidt

Members of the Afro-Brazilian religion Candomble perform a ceremony with visitors during "Long Nights of Religions" as part of the German protestant church congress Kirchentag in Berlin, Germany,May 25, 2017. REUTERS/Axel Schmidt

Hindu devotees and visitors attend "Long Nights of Religions" at Sri Mayurapathy Murugan Hindu-Temple as part of the German protestant church congress Kirchentag in Berlin, Germany, May 25, 2017. REUTERS/Axel Schmidt

Members of the Afro-Brazilian religion Candomble perform a ceremony with visitors during "Long Nights of Religions" as part of the German protestant church congress Kirchentag in Berlin, Germany, May 25, 2017. REUTERS/Axel Schmidt

The Temple Ile Oba Sileke of the Afro-Brazilian religion Candomble is open for visitors during "Long Nights of Religions" as part of the German protestant church congress Kirchentag in Berlin, Germany, May 25, 2017. REUTERS/Axel Schmidt

A Hindu devotee attends "Long Nights of Religions" at Sri Mayurapathy Murugan Hindu-Temple as part of the German protestant church congress Kirchentag in Berlin, Germany, May 25, 2017. REUTERS/Axel Schmidt

Participant chat during the German protestant church congress Kirchentag in Berlin, Germany, May 25, 2017. REUTERS/Fabrizio Bensch

A participant takes a rest during the German protestant church congress Kirchentag in Berlin, Germany, May 25, 2017. REUTERS/Fabrizio Bensch

Participants attend the German protestant church congress Kirchentag in Berlin, Germany, May 25, 2017. REUTERS/Fabrizio Bensch

Melinda Gates, co-founder of Bill & Melinda Gates Foundation talks to German Minister of Economic Cooperation and Development Gerd Mueller as they attend the German protestant church congress Kirchentag in Berlin, Germany, May 25, 2017. REUTERS/Fabrizio Bensch

Melinda Gates, co-founder of Bill & Melinda Gates Foundation attends a discussion during the German protestant church congress Kirchentag in Berlin, Germany, May 25, 2017. REUTERS/Fabrizio Bensch

People of different faiths gather at Gendarmenmarkt square during the German protestant church congress Kirchentag at in Berlin, Germany, May 25, 2017.

People of different faiths share a meal during the German protestant church congress Kirchentag at Gendarmenmarkt square in Berlin, Germany, May 25, 2017. REUTERS/Axel Schmidt

People hold a poster reading "Now even more" as they attend a discussion by German Chancellor Angela Merkel and former U.S. President Barack Obama at the German Protestant Kirchentag in front of the Brandenburg Gate in Berlin, Germany, May 25, 2017. REUTERS/Fabrizio Bensch

Participants pose for a picture with a person in a bear costume during the German protestant church congress Kirchentag near the Brandenburg Gate in Berlin, Germany, May 25, 2017. REUTERS/Fabrizio Bensch

Former U.S. President Barack Obama speaks during a discussion at the German Protestant Kirchentag in front of the Brandenburg Gate in Berlin, Germany, May 25, 2017. REUTERS/Fabrizio Bensch

People hold posters as they attend a discussion by German Chancellor Angela Merkel and former U.S. President Barack Obama (neither pictured) at the German Protestant Kirchentag in front of the Brandenburg Gate in Berlin, Germany May 25, 2017. REUTERS/Fabrizio Bensch

Former U.S. President Barack Obama waves at the end of a discussion at the German Protestant Kirchentag in front of the Brandenburg Gate in Berlin, Germany, May 25, 2017. REUTERS/Fabrizio Bensch

German Chancellor Angela Merkel and former U.S. President Barack Obama wave at the end of a discussion at the German Protestant Kirchentag in front of the Brandenburg Gate in Berlin, Germany, May 25, 2017. REUTERS/Fabrizio Bensch TPX IMAGES OF THE DAY

German Chancellor Angela Merkel waves as former U.S. President Barack Obama talks to Sierra Sims at the end of a discussion at the German Protestant Kirchentag in front of the Brandenburg Gate in Berlin, Germany, May 25, 2017. REUTERS/Fabrizio Bensch

People attend a discussion by German Chancellor Angela Merkel and former U.S. President Barack Obama at the German Protestant Kirchentag in front of the Brandenburg Gate in Berlin, Germany, May 25, 2017. REUTERS/Fabrizio Bensch