Cardinal Cahal Daly has said secularism is "more anonymous and more subtle than either Nazism or Communism were" as a threat to faith.
Speaking at a Mass in Knock, Co Mayo, he said he believed "today's secularism is seductive and persuasive. It is part of the air we breathe; it fills the airwaves whose sights and sounds greet our ears and our eyes all day and all night long. It tells us, either directly or implicitly, that the church of Christ is dying, that intelligent people and young people have no longer any interest in the church," he said.
Secularism "tells us that Christ's teaching belongs to a credulous and unscientific or superstitious and poverty-stricken past", he said. "It suggests that all faiths are equally true and equally false; that the Bible is a purely human creation, a collection of primitive folk traditions; that all lifestyles are equivalent; that morality is a matter of opinion; that nothing is sinful in itself.
"How quickly we have forgotten the lesson of the Holocaust, the lesson of Stalinism. We should be the last of all generations to forget the propensity to evil which is in human beings as a result of original sin. We should be the last to forget our own capacity for sin, indeed our own sinfulness," he said
The Cardinal was speaking in the context of the canonisation of Sister Faustina Kowalski on Sunday. Saint Faustina, who died in 1938 aged 33, was a member of the Congregation of Our Lady of Mercy and promoted devotion to divine mercy, particularly through confession. Cardinal Daly gave "thanks to the Lord with gladness in our hearts for adding another young woman of our time to the list of saints".
He said the event must bring joy to Pope John Paul as the nun was born in Crackow, and the Pope as archbishop there had started the process for her beatification in 1963.
"It was undoubtedly through his influence that the Congregation of the Holy Office, as it then was, reversed the decree which it had issued in 1959, prohibiting the spread of devotion to divine mercy in the form in which Sister Faustina had proposed it," Cardinal Daly said.
The doctrine of divine mercy, which Saint Faustina had taught, helped to sustain the faith and hope of Poles during the second World War and during "the long years of communist oppression which followed them", he said.
The truth of divine mercy was "even more relevant in our own time" when the threat to faith from secularism was so great. He hoped the spread of devotion to divine mercy would help to renew the practice of "good, sincere and honest and trusting confession".
The decline in confession or reconciliation may indicate "a weakening of our awareness of sin in our own lives", he said.
