Middle East Concern and Open Doors have been encouraging the worldwide day of prayer.
On Sunday Syrian state media reported 12-hundred people were due to be evacuated from rebel-held areas, in return for a similar number from east Aleppo.
Buses have started entering the besieged city to resume the withdrawal of civilians and wounded.
Aid organisations are supervising the evacuation, which ground to a halt on Friday because of a disagreement with pro-government forces.
There are reports that civilians have been sleeping rough in freezing temperatures and trying to escape the city on foot amid gunfire.
Speaking to Open Doors from the Syrian city of Homs, Deacon Bassam Sawan said: "Churches will come together to pray for peace in Syria.
"This day is important because of what Christ said: 'What is impossible with man is possible with God'.
"This day is beyond all geographical and cultural barriers between people from east to west. It will unite hearts and minds with Christ in order to pray and seek the Lord for peace in our land."
Points for prayer from Middle East Concern and Open Doors can be found here.
