The Archbishop of Armagh, Dr Sean Brady, has called on all those who voted for the Belfast Agreement "to once again renew their hope in the promise which that historic agreement contains".
In his homily at Mass on Christmas Eve in St Patrick's Cathedral, Armagh, he said: "The Belfast Agreement represents not alone the only hope, but in my opinion, an excellent hope of establishing once and for all those right relationships and that mutual understanding which we call, and which actually are, genuine peace.
"In this season of peace and goodwill, the support of prayers for reconciliation and for the continuation of the normalisation of relationships is essential."
Dr Brady said a lasting peace could only be built and maintained by people of vision, by people who had the capacity to think and work for the future.
"Those people need the support of all who are really on the side of peace if they are to continue to dedicate their lives and take risks for the benefit of generations yet unborn." He said: "We praise God for the improvement in the relations between those who were previously at enmity with each other. We recognise the good work done by so many courageous people in so many areas of life.
"At the same time we realise that events such as shootings and bombings, expulsions and punishment beatings illustrate the absence of right relationships in certain areas, the absence of total peace.
"The impasse over policing, decommissioning and demilitarisation indicates an atmosphere of suspicion, distrust and absence of goodwill. Such a situation does not give great hope of right relationships being easily or speedily established.
"There is still an amount of road to travel. There is need for patience - immense patience - and a renewed commitment to the search for a lasting settlement."
The Church of Ireland primate, Dr Robin Eames, said on Christmas Day that life had become far too cheap in Northern Ireland.
Preaching in St Patrick's Church of Ireland Cathedral, Armagh, he said: "Bullying, intimidation, armed robbery, the mafia-style outlook in which decent people feel fear even in their own homes, the so-called `punishment beatings', all are examples of how cheap life has become."
Thirty years of terrorism had given way to a new culture of "respectable violence", he said.
"Too many instances of violence appear to be immune from detection or prosecution. People talk to me of being afraid to tell what they know or what they have seen. They are afraid of the consequences of `speaking up'."
It was a situation which the government needed "to face up to with realism and determination. Political progress is essential, but political progress can never be a substitute for the exercise of basic law and order on our streets and in our homes. Political progress can never be an excuse for tolerating the law of the bully boys," he said.
