German Chancellor Angela Merkel wants Protestants and Catholics to emphasise what they have in common as the nation prepares for celebrations marking the 500th anniversary of the start of the Protestant Reformation.

"Especially in a very secular world, we should always stress what is common in the Christian religion," Merkel, who is the daughter of a Protestant pastor, said Monday, according to Reuters.

Merkel made her comments at the Evangelical Church in Germany's (EKD) annual synod near Luebeck, where Protestant leaders are working to make the "Luther Jubilee" in 2017 more ecumenical by involving Catholics as well.

But bringing together the two church bodies for an event that marks such a major split in church history could prove difficult even in the seemingly minor details.

"I've learned that even the word 'jubilee' used in connection with the Reformation can give rise to discussions," Merkel said. Catholics ascribe special meaning to the term "jubilee years" and as such would prefer to have the anniversary event called a commemoration.

In an article that appeared in the Frankfurter Allgemeine newspaper in late October, EKD Church Office Vice President Thies Gundlach said, despite their differences, he hopes a "wonderful friendship" will develop between Catholics and evangelicals as a result of anniversary events.

The "many ecumenical achievements that render visible the truth and beauty of Christian faith 500 years after the Reformation and 50 years after the Vatican II" are grounds for joint celebration, wrote Gunlach. These achievements include agreeing on the importance of Scripture, baptism and a general acceptance of ecumenism.

But Bishop Gerhard Feige, the top Catholic official working with Protestants, said in a recent statement that it is possible that Catholics will participate in the celebration, though there are some concerns.

"Catholic Christians consider the division of the western Church as a tragedy and – at least until now – do not think they can celebrate this merrily," said Feige, according to Reuters.

Feige made the comments on on October 31 – Reformation Day – which marked the anniversary of the date in 1517 when Martin Luther posted his 95 Theses and the Reformation essentially began. Luther's theses were posted to the Castle Church door in Wittenburg, Germany as a challenge to the Catholic Church's doctrinal position on the sale of indulgences.

In preparation for the quincentennial celebration, the EKD and the Catholic Church have plans to write a book on Christianity together in 2013 and to hold a joint Bible conference in 2015.

Reuters reports that EKD President Nikolaus Schneider told the synod that there may also be a reconciliation service scheduled for 2017 "that recognises before God all the injuries both churches inflicted on each other".