The World Council of Churches is inviting member parishes and congregations on a "pilgrimage to Busan".
The South Korean city is the venue for the WCC's 10th Assembly in October next year.
To help churches prepare, the WCC has produced a new online publication exploring the assembly themes of Christian unity, justice and peace.
Entitled Pilgrimage to Busan: A Journey into Ecumenical Christianity, the six-unit resource is designed for use by congregations in study groups, adult forums, or for a day-long retreat.
The publication is designed to help churches engage in the overall theme of the assembly - "God of life, leads us to justice and peace".
The assembly takes place in Busan from 30 October to 10 November 2013.
"As we move toward our 2013 assembly in Busan, we can reflect on who we are, and what we are called to do as Christians," said the WCC general secretary, Rev Dr Olav Fykse Tveit.
"I hope that Christians everywhere will join this journey, exploring the exciting themes and issues of world Christianity using this resource. Meeting each other in this way, Christian communities are joined in solidarity for justice and peace."
The units in the resource look at specific situations, like that of Orthodox churches in Eastern Europe, or Dalit Christians in India.
"Ecumenism is really a movement for renewing Christianity. It entails a conversion in one's scope of concern, and it begins with encountering Christians very different from oneself," said resource writer Reverend Dr Karen L Bloomquist.
"Through stories, reflection, prayer and exploring other linked resources, people can deepen their awareness of other Christians and their own discipleship."
Translations of the resource in French, German, Spanish and Korean are underway.
Churches are invited to provide and distribute additional translations.
The resource can be accessed here