Three Presbyterian pastors, a Lutheran and a Mennonite pastor were named as targets in a threat that was printed and circulated in the name of the Black Eagles neo-paramilitary group on 11 January.
Revd Milton Mejía, Revd Jairo Barriga and church elder Germán Zárate (pictured) from the Colombian Presbyterian Church, who work in the Atlantic Coast city of Barranquilla, were among a list of names on the threat.
The letter said: "We know where you live and your organizations are also in our sights.
"Know that we are coming for you."
In a joint statement the Churches involved said they believed the threat had come because the men were offering help to victims of violence, as well as in peace-making and reconciliation.
"We believe these threats to be religious persecution as they are clearly threatening the development and free practice of our pastoral and humanitarian work with those who suffer the consequences of the armed conflict, and our participation in peace making for Colombia as the Gospel requires of us," it said.
Church leaders have long been a target of armed groups on all sides of the internal conflict in Colombia.
While guerrilla groups have tended to target church leaders because of an ideological opposition to religion, neo-paramilitary groups often view church leaders as opposing their aims because their message often runs counter to the groups' objectives.
Mervyn Thomas, Chief Executive of Christian Solidarity Worldwide, said: "We are deeply concerned for the welfare of Reverend Milton Mejía, Reverend Jairo Barriga and Elder Germán Zárate, as well as for all the others named in the threat issued by the Black Eagles.
"While we are pleased with the progress made in the ongoing peace dialogues between the FARC and the Colombian government, we repeat our call to the Colombian government to take serious steps to eradicate paramilitary groups and to address the threat they pose to human rights and to stability in Colombia.
"In the meantime, we call on the European Union, the United Kingdom and the United States to raise this case as a matter of urgency with the Colombian government, and to monitor closely the welfare of the men and women who have been threatened."