Pope Francis’s visit to Sweden to commemorate the five hundredth anniversary of the start of the Protestant Reformation was greeted with varied and predictable responses.

Progressives, both Protestant and Catholic, hailed the meeting as a new step towards full re-union while conservatives on both sides of the Wittenberg Door observed the smiles, the ceremonies and the signatures with cynicism and reserve.

Both sides are unrealistic.

Those who believe the reunification of the Catholic and Lutheran churches is just around the corner are too optimistic while those conservatives who mutter, “If they want reunion let them become Catholic…” are too pessimistic.

The ecumenical showpieces that feature a pope and Protestant leaders are just that: showpieces that mark an anniversary here, the closing of theological talks there or the beginning of a new effort to cooperate in the promotion of justice and peace.

While the showpieces make good news stories, there are four foundations of ecumenism that keep us grounded.

The first two principles are the core ideas of the second Vatican Council. The Italian word aggiornomento means “to bring up to date.”

The fathers of the church wanted to modernize the Catholic faith, and being affirming rather than antagonistic towards other Christians was part of the new spirit in the church. To be modern was to put old animosities aside and accept  Orthodox Christians as well as those from the Protestant tradition as “separated brethren.”

The task of bringing the ancient faith up to date was balanced by the second principle, expressed by the French word resourcement. This is the idea that for the church to be renewed properly we must turn to the original sources of the faith.

In the decades building up to the council new discoveries were made about the earliest ages of the church. Archeological finds, textual research and Biblical and liturgical discoveries enabled Christian scholars to understand the beliefs, traditions and devotions of the first Christians as never before.

Both Protestant and Catholic scholars were making the new discoveries and both sides saw the principle of resourcement as a great ecumenical gift. Instead of continuing theological debates from the sixteenth and seventeenth centuries, both the Protestants and Catholics believed they could share the faith that unified all Christians before the divisions of the Reformation era.

With aggiornomento and resourcement firmly in mind, theologians conceived a new method for ecumenical discussion which might be called “theological translation.” The terminology and definitions that had been defined and defended by one side and denied and denounced by the other would be set aside.

Instead of using the same theological language and doctrinal definitions from the Reformation and Counter-Reformation eras, the ecumenists would explore together the beliefs, language and definitions of the early church looking for grounds of agreement. In doing so they would skirt the centuries old terminology and mindset now encrusted with centuries of dead end debates.

Together they would devise new language to discuss the same beliefs—language that was at once consistent with the thought of the early church while, at the same time, accessible, agreeable and up to date.

While these principles have allowed for real progress and genuine optimism, they have also brought about confusion and dismay. Christians on both sides who like their religion cut and dried and neatly defined, are disturbed by the novelty of language and vague terminology used in the ecumenical documents.

Those who are suspicious of the process accuse the ecumenists of deliberate obfuscation and ambiguity in order to reach an artificial consensus.

When the reports are published, too often the only enthusiasm one senses is on the part of the ecumenists themselves. Thrilled with their progress, they fail to see that Christians in both Catholic and Protestant pews are unimpressed.

Ordinary Christians on both sides are often more stark in their assessment. They see the whole enterprise as being a talking shop for the intellectual elite, and can’t see what the point might be.

Furthermore, many Catholics see the new obstacles that Lutherans and Anglicans have put in the path of church unity and are understandably cynical. “The pope told them ordaining women and having same sex weddings would be a grave obstacle to unity and they just did it anyway.”

When faced with the setbacks, confusion and lack of enthusiasm, it is all the more important to remember the fourth principle of ecumenism: that we are in this for the long haul.

Relationships with the Protestants have really only begun to thaw. It was in the 1960s that Catholics and Protestants began to embrace one another. We should not imagine, therefore, that formal reunion will happen anytime soon.

After all, the Great Schism divided the Catholic Church from the Eastern Orthodox in 1054. Almost a thousand years have gone by and we’re still working on that one.