Fr Paddy O'Kane, parish priest for Ballymagroarty in the diocese of Derry, says many children never return the following Sunday and then lambasts some families who "just want to throw a party".
Writing on his parish website he says: "Then it's reduced to an orgy of sentimentality and materialism with miniature brides and bouncy castles and bursting bank accounts."
He says it is in this context that he has just written a letter to the families of the children who are making their First Communion this year.
In it, he also reminds parents that when their child was baptised they promised to bring him/her up in the practice of the faith.
The letter also states: "That promise will only be kept if this is not a ''once off'' occasion but the beginning of a new stage in his/her faith journey. Simply put, you must bring him/her to back to Mass again every weekend after his/her First Communion. "
In another attack on a perceived lack of reverence, Fr O'Kane also criticises people who talk in church:
"It is not acceptable to engage in conversation at any time but most of all at Holy Communion....I beg you to use this time by saying your own prayers and thanking God for all his blessings especially your child whose attitude to reverence in church and Holy Communion will be inherited from you and the kind of example you give."
Finally, he ends with what he calls a "Word of Wisdom" line:
"Children are like blotting paper – they soak up all they see and hear!"