The Catholic and Church of Ireland bishops of the Clogher diocese, which is mainly in the North, have said people who encouraged reconciliation were often left isolated.
They needed more active and positive support from all who belonged to the Christian churches, the bishops said in a joint pre-Christmas message.
Dr Joseph Duffy, the Catholic bishop, and the Right Rev Brian Hannon, of the Church of Ireland, said there was in the North "a deeply embedded culture of insidious sectarianism and political extremism which continues to devalue the spirit of the Christian gospel".
The bishops applauded the efforts of those who continued to raise awareness of these problems and who encouraged reconciliation at every opportunity.
"In accepting our responsibility for what has happened in our divided community over the years", they acknowledged the challenges change would bring.
They praised the North's politicians for their "significant success" in advancing the peace process.
"We compliment them warmly and pray that their painful and courageous decisions will be rewarded by the fruits of a just and lasting peace," they said.
The core problem remained lack of trust. "Initially, and given our history, trust needs a spirit of forgiveness." But it was not sufficient to appeal to individual acts of heroic forgiveness.
"The community at large must be open to the healing and growth of relationships. Only in this way will sectarianism be replaced by a culture of sharing and listening that respects difference and leads to genuine peace," they said.
