Archbishop of Dublin Diarmuid Martin will speak about the "dangerous culture of violence in Ireland" during his New Year's Day address.
Appearing to reference the Kinahan-Hutch feud, he calls for an end to gangland and drug related violence.
Martin says gang figures are "totally blinded by their own selfish interest in the drug trade, a trade in death which is of such enormous financial interest that it leaders feel that they must kill to keep their power."
New Year's Day will mark the Catholic Church's 50th World Day of Peace. This year's theme, as chosen by Pope Francis, is Nonviolence: A Style of Politics for Peace.
Non-violence, says Martin, is a sign of strength, not weakness. "It is a sign which recognises that lasting peace can only be achieved by peaceful means."
"Violence only leads to retaliation and further grief and those who seem to think they are stronger by resorting to violence are left in an insecurity which they know no sophisticated modern security systems can really protect them or their loved ones."
He calls on young people to learn from an early age that "divisions can be overcome and that tolerance and respect, but also patient understanding and mercy, are the strong weapons for relationships that endure, in the personal as well as in the social and political sphere."
