It was taken during a break-in at the home of the Right Reverend John Christie in Helensburgh.
The ring has a large amethyst stone and bears the Church's Latin motto "nec tamen consumebatur", meaning "yet it was not consumed" - an allusion to the biblical story of the burning bush.
Presents and a wallet were also stolen in the robbery that took place some time between 11pm on Wednesday and the early hours of Christmas Eve.
Det Insp Ross McCallum, of Strathclyde Police, said: "Thefts from your home are difficult to deal with any time of year, but especially at Christmas."
The ring is described as gold with a large amethyst stone and engraved with the words Church of Scotland. "Whilst it has a monetary value it is, more importantly, of significant historical importance to the Church," McCallum said.
The Church of Scotland is making an appeal for the ring's return.