Rev Nadim Nassar spoke ahead of a truce due to start at sunset on Monday evening but he warned the agreement is not a permanent solution to the "proxy war".
He told Premier's News Hour: "All the negotiations are happening between Russia and America, and, actually, the Syrians have very little to do with the whole negotiations. That is the tragedy in the Middle East; it is a mini world war."
Hours before the ceasefire, the Syrian president Bashar al-Assad spoke of his government's determination to "reclaim every area from the terrorists, and to rebuild."
Agreed by US Secretary of State John Kerry and Russian Foreign Minister Sergey Lavrov on Saturday and supported by the Syrian government, the deal allows Assad to continue strikes against Islamic State and al-Qaida-linked militants for another week, before the US and Russia take over the role.
The run-up to the ceasefire was marred by bloodshed, with the Britain-based Syrian Observatory for Human Rights reporting more than 90 civilians died in presumed Russian or government air attacks in Idlib and Aleppo on Saturday.
It is unclear to what extent the truce, which hopes to allow the creation of UN aid corridors into the northern city of Aleppo, will be respected by rebel factions.
Rev Nassar added: "As long as Russia and the United States, with their allies, don't agree on how the future of Syria might be, we will have war and we will have still people killing each other, bombing and shelling.
"I pray for Syria as well as I pray for humanity to wake up to the purpose of God's creation, to live in peace and to live in love and to reflect His image in us. We are not doing that and the Church is not doing that. We are doing very little to reflect this image."
According to Unicef the conflict in Syrian has caused "the largest humanitarian crisis since World War Two", since it emerged five years ago.