The three organisations include the World Council of Churches (WCC), the World Alliance of Reformed Churches (WARC) and the Council for World Mission (CWM).
Sixty theologians, church leaders and activists from Africa, the Caribbean and the Americas attended the event called "Abolished, but not Destroyed: Remembering the Slave Trade in the 21st Century" held 10 to 14 December in Runaway Bay, Jamaica.
The conference marked the 200th anniversary of the passing of the Abolition of the Slave Trade Act of the British House of Commons. Between the 16th and 19th centuries an estimated 15 million Africans were forcibly removed from their homes and shipped across the Atlantic Ocean to become slaves in the Caribbean and the Americas.
"Many churches were actively involved in the transatlantic slave trade in Africans and colonialism; hence the church's mission has been seriously compromised and betrayed by its historic complicity with two of the most blatant forms of oppression that occurred within the 16th and 19th centuries," the statement says.
"Further, the church's pastoral and prophetic roles in the contemporary period are obstructed by its voluntary amnesia about its corporate sin and silence regarding the past - as well as regarding the present - responsibility to bring justice to those still suffering from the legacy of the transatlantic trade in Africans."
The church bodies also stated that "while there have been some acts of repentance and confessional statements made by some churches" these have largely "not been effective enough" in eradicating white supremacy, systemic racism and the ongoing legacy of the transatlantic trade in Africans.
The international conference called on churches that were complicit in the slave trade to name the trade - and other modern forms of slavery - a sin.
The conference stated that reparation is needed by both church and society but that reparation is much more than a financial issue.
"The process of reparations requires the restoration of relationships that affirm the dignity and humanity of all parties in order to repair what has been broken. Reparation also challenges the perpetrator to confession and repentance and minister restoration and healing to those who have been exploited.
"The transatlantic trade in Africans destroyed the roots of nation building and enriched the oppressors to build its nations and states. Thus, we believe that mere financial aid is no replacement; rather, full nationhood and community restoration of peoples impacted should be the condition of reparations."
WCC representative Adele Halliday of Canada said that the challenge now is to move beyond statements and make the issues discussed in Jamaica tangible in the church. Added Lois McCullough of the United States, another WCC representative, "Churches need to atone and act."
Jennifer Ayana McCalman of Nevis, a CWM delegate, said, "What has been done in one generation has effects in the generations following. If we don't deal with these consequences from the slave trade then we, the church, are living in denial."
WARC general secretary Setri Nyomi, who also attended the event, expressed thanks for the collaboration with WCC and CWM.
"The statement sends a strong message challenging churches to look at their own past complicity in the evil of slavery and the slave trade and be at the forefront of exposing modern forms of slavery and oppression of people based on caste, race, gender or economic status," Nyomi said.
The conference was hosted by the United Church in Jamaica and the Cayman Islands and supported by the Caribbean Conference of Churches as well as the Jamaica Council of Churches.