The pontiff said his remarks applied to all divorce cases, not just those involving Roman Catholics. The permanence of marriage is part of the divine, natural order and applies to everyone, he said.
He made the comments during an address to the Roman Rota, a Vatican court that handles annulments, a process by which the church effectively declares that a marriage never took place.
The Roman Catholic church does not recognize divorce, only annulments.
John Paul said that divorce has had ``devastating consequences that spread in the social body like a festering wound'' and infected a new generation.
He acknowledged it would be hard for judges to refuse to hear divorce cases because there is no "conscientious objector status." But taking part in such cases amounted to collaborating with an evil, he said, urging judges and lawyers to instead devote their efforts to reconciling couples.
The comments drew criticism from across the political spectrum in Italy.
``The pope is making a tremendous mistake. This is still a lay state, despite the Vatican. His behavior is ever more fundamentalist,'' the Radical Party said.
Alessandra Mussolini, a member of Parliament from the conservative National Alliance, said John Paul's comments were an attempt to "turn back time" and reopen a question that society had resolved long ago.
Mussolini, whose grandfather was the late Fascist dictator Benito Mussolini, said divorce was, in some cases, the best option for the children of warring parents "because it breaks the spiral of hate and terror for them."