The service took on a distinctly international flavour as hand drums accompanied African and African-American worship songs, and responses were sung by the congregation in the South American language of Guarani.
The main sermon was delivered by the Rev Dr Bernice Powell Jackson of the United Church of Christ in the USA, who thanked Dr Kobia for his "leadership as an unwavering witness for justice and peace in the world on behalf of the WCC".
She spoke of the many people in the world still suffering because of conflict, oppression, poverty, occupation and the impact of climate change before appealing to Christians to come back to the invitation through the prophet Isaiah to come, buy and eat without cost.
"The moment of opportunity is upon us," she said. "Come back to the spirit of God. Come back and rebuild the community. Come back and make real the promise of joy, the promise of peace … For the people await our leadership. They await our witness, they await our action, they await our truth, they await our compassion."
Dr Powell Jackson went on to thank the former General Secretary for reminding Christians that they were called by God to bring hope to a world "threatened by its hopelessness".
"Your gift has been to give the courage to hope," she said, quoting the title of Dr Kobia's report to the Central Committee last Wednesday, "Courage to hope".
Dr Powell Jackson concluded by telling the congregation of an old African American story about slaves who had forgotten how to fly until a wise old black man came to each of them and whispered in their ear "kulibah", the word that reminded them they were able to fly home to a land of abundance and love.
"We were born to fly," she said. "If we come back to God, if we find our way home, then we too shall experience God's promise."