A consultative conference of the Irish National Teachers' Organisation (INTO) has been told that "in the Monday morning religion class, neither the teacher nor half the class might have been to church the previous day".
Mr Joe Conway, of the INTO's education committee, told a conference on "The Teaching of Religion in a Changing Society" in Mullingar at the weekend, that "in many cases the teacher is the first and last contact the child will have with their religion".
He recalled how a colleague remarked recently: "Five years ago, if you asked a child in infants to name a priest, they would all name Father Jack or Father Ted; now they don't even know them."
A lot of primary school children only saw their local priest when the teacher brought them to confession, Mr Conway said.
"Often the only religious discussion a child will have will be with his or her teacher and yet the teacher may not necessarily believe or practise the faith of the school," he said.
Few families now attended Mass regularly and fewer still prayed together at home, he said. "Teachers in infant classes comment on the number of children who come to school unable to bless themselves. In more senior classes it's not unusual to find that children can't say the Our Father, Hail Mary or Glory Be on their own," he said.
In practice, children were "learning their values and code of morality from television and pop acts", he said. And while teachers may agree with the parents on matters of morality, they "must teach the doctrine of the school in which they teach", he said.
There were further challenges. "With the number of different nationalities in our classes we are facing members of religions we know nothing about," he said. This was in addition to the growing number of children whose parents profess no faith.
Dr Pádraig Hogan, of the Education Department, NUI Maynooth, told the conference it would be "an act of cultural obliteration" to remove religious traditions and inheritances of learning from schools.
"Some would argue that religion has no place in an education system that is almost wholly sustained by public funds. Such a view, I'd suggest, is as dogmatic as the traditional one it is usually pitted against," he said.
Much thoughtful work needed to be done on how religious traditions are to be experienced and engaged with in the future. And the criteria for guiding such thinking would have to be defensible educational criteria as distinct from evangelical assumptions inherited from the past, he said. "There must be clarification of the difference in role between teachers on the one hand, and those in religious ministry on the other," he said.
An INTO survey, conducted last month, found that primary teachers in the State were deeply unhappy about the lack of involvement by clergy and parents in the religious education of children.