"On several occasions, the Holy Father encouraged the churches to journey together in witnessing to their faith and in facing our contemporary challenges," he said, adding that walking together in this way helps Christians to better appreciate their common heritage and the things they already have in common.
It also allows Christians to understand the differences that still exist, particularly on doctrinal or moral issues, he said. However, while overcoming points of theological divergence is an important part of achieving unity, there is more to the process.
"It also must include collaboration for those who are in need, and for the many victims of wars, injustice, and natural disasters," Koch said, and stressed the need to pray both for and with one another.
Though the Pope's official schedule has yet to be released, the cardinal said the day trip would likely begin with a courtesy visit to Swiss President Alain Berset, after which Francis will head to the WCC headquarters for a moment of ecumenical prayer in the center's chapel.
He will also attend a special session of the WCC's Central Committee dedicated to the anniversary celebration. Afterward, the Pope is expected to celebrate Mass for the Catholic community in Switzerland before heading back to Rome.
While the majority of the founding members came from Europe and North America, currently the bulk of the WCC membership is in Africa, Asia, the Caribbean, Latin America, the Middle East and the Pacific.
This change reflects wider shifts in the presence of Christians throughout the world, Koch said, and "can be an encouragement for Europeans to rediscover Christianity."
Also present at the March 2 presentation of the trip was Rev. Olav Fykse Tveit, secretary general of the WCC. Speaking to journalists, he said the Pope's trip is "a landmark visit" and "a sign of hope not just for us, but for all who long and work for unity in the world."
"We see it as a sign of how we as Christian churches can affirm our common calling and our mission of [serving] Christ together," he said, adding that visits such as this are steps that help build hope for future generations.
"Hope is a critical dimension of our lives that is essential to be able to handle suffering" and the many challenges the world faced, he said, and prayed that the Pope's visit would be a concrete sign of this hope.
Elise Harris was senior Rome correspondent for CNA from 2012 to 2018.