The Church of Ireland Primate, Archbishop Robin Eames, has told loyalist killers that the vast majority of Protestants utterly condemn their recent indiscriminate murder of Catholics.
And in a message directed to the Catholic community, Archbishop Eames emphasised: "Such deeds are utterly immoral. They are not committed on our behalf or in our name".
The Archbishop was speaking at the annual service of the Church of Ireland Men's Society in the Cathedral Church of St Patrick, Armagh.
Addressing loyalist paramilitaries, he said: "You have no mandate for killing. Killing is a sin.
"There is no reason which can be offered which can possibly justify the murder of a human being, Protestant or Catholic, in Northern Ireland".
Speaking about the moral element of political dialogue, Archbishop Eames said the pressure on political representatives to make progress was intense at present.
"But we need to realise that the peace process through political dialogue involves the morality of commitment, integrity and a recognition that so much depends on progress being made through democratic decision-making."
They wanted their politicians to engage in debate, argument and seek agreement, but the community deserved the knowledge that genuine efforts were being made to address the division in society, he said.
"The morality of genuine political dialogue must never be allowed to give way to the immorality of violence."
Archbishop Eames warned: "We have come a long way, but we also have a very long way to go".
Taking risks for peace had a truly Christian foundation. The morality of peace carried with it the assurance that "blessed are the peacemakers."
The Archbishop said there was a moral issue concerning what sort of place they wanted Northern Ireland to become.
"We have seen and experienced the failures of the past. History has not always been kind. Now we must make every effort to reach a society in which the truly Christian principles of fairness, justice, peace and common understanding underline all our dealings".
He cautioned that they could not afford to move forward with feelings of alienation, hurt or injustice dictating the attitudes of any one community.
"Threatening behaviour, attitudes, words or actions must become not just unlawful; they must become socially unacceptable. We must grasp the opportunities for a lasting and just peace."