The European Evangelical Alliance (EEA) has accused Belarus of "using human beings as pawns" in the migrant crisis on the country's border.
It follows accusations from the European Union that Belarus has been flying in thousands of people from the Middle East and pushing them to cross into Poland, Lithuania and Latvia in response to European sanctions.
The EEA's statement signed by its General Secretary, Thomas Bucher, agreed with the EU that this is the motive of the Belarussian government of President Alexander Lukashenko, whose authoritarian leadership has drawn EU and NATO condemnation.
The Belarussian government is "choosing to invite and facilitate the travel of migrants from the Middle East to Belarus and then taking them to the EU border", the EEA said.
The statement acknowledged that "it is understandable that Latvia, Lithuania and Poland want to prevent migrants from crossing that border. And they do not want to do anything to encourage more people to come".
"However, 1000s of men, women and children are now suffering terribly: those still in Belarus, living without food or shelter. And those who have crossed into the EU are having to hide in the forest or are being kept in terrible conditions, often in closed camps," the EEA said.
It warned that "as winter sets in, this cannot continue".
"Lives of human beings are far more important than politics. A humanitarian catastrophe is developing. Terrible and tragic stories are emerging of how these migrants are faring," the EEA said.
It has called on the EU and governments involved "to remember the human beings at the heart of this matter".
"These people deserve compassion," the EEA said.
"They must not be ignored or demonised. When human beings are suffering, it is not enough only to engage in blame games, imposing more sanctions or building fences."
The statement concluded: "The European Evangelical Alliance calls upon Christians to pray that this crisis can swiftly be resolved in a way which upholds Europe's Judaeo-Christian values of human dignity, justice, compassion and solidarity."