The Haass talks were a missed opportunity, according to Northern Ireland's four main churches.
Speaking on their behalf, the Right Rev John McAreavey said it will be very serious for Northern Ireland's society if a consensus isn't reached.
The Catholic Bishop of Dromore called on politicians to sustain the momentum of the talks, which focused on the issues of flags, parades and the past.
Bishop McAreavey was nominated as a spokesman by leaders of the four main denominations, which have urged the Executive to develop an "acceptable process".
The churches also said the responsibility did not just lie with political leaders, but called on every member of the community to be "instruments of reconciliation and peace-building".
Bishop McAreavey said that in a divided society, nobody's vision was translated perfectly into action, adding: "If we were ultimately to fail in this process to reach consensus, I think it would be very serious for us and for our whole society, for our young people and for everyone trying to work for a better society."
The negotiations, chaired by former US diplomat Richard Haass, drew to a close on New Year's Eve without agreement.
Sinn Fein and the SDLP have endorsed the proposals, but the DUP, UUP and Alliance reject elements of the Haass blueprint.
The leaders of the parties at Stormont are due to meet this week to discuss the way ahead.
Secretary of State Theresa Villiers said it was wrong to say that the talks had failed.
DUP MP Jeffrey Donaldson said problems within the Haass proposals needed to be addressed.
He said: "What we need to do is close the gap in the areas where there is not agreement. I believe that can be done."
Sinn Fein's Gerry Kelly said: "In the whole, this is a document that we can move on with and I think that's what three of the parties here are saying."
UUP leader Mike Nesbitt said the Haass document had "airbrushed terrorism out of history".
"I spoke to many victims and survivors who encouraged me not to go near the Haass deal, including Innocent Victims United who represent thousands of victims – they didn't want it," he said.
The SDLP's Alex Attwood said: "There are issues within this document where we think, through implementation legislation, that we can get even better. But do not now put in jeopardy the best chance since 1998 to deal with some of the biggest issues that we've never faced up to before."
Naomi Long of Alliance said the party was concerned about what was left out of the proposals.