The current restrictions on first communions and confirmations "defy common sense", according to the Archbishop of Dublin.
Archbishop Dermot Farrell says he believes the current rules are "discriminatory and irrational".
The Government has said communions and confirmations shouldn't go ahead for now.
However, some bishops and priests across the country are still planning to go ahead with the ceremonies in the coming days and weeks.
Archbishop Farrell told The Hard Shoulder he has written to parishes in the Dublin diocese to tell them he believes the events should be postponed until autumn.
However, he is not going to get in the way of priests and parents who decide to push ahead with more immediate plans.
He said: “There’s a number of parents and indeed parishes out there who’ve drawn the conclusion the current guidelines are discriminatory and perhaps irrational.
“I believe they are irrational. When I look around me… there’s a unique situation. [Sacraments] are prohibited from taking place - this seems to be because there’s a risk of consequential family gatherings."
He said the risk of gatherings outside an event also apply to the likes of bars, restaurants, sporting events, weddings, funerals and more.
He added: "There was even a big bash in the Merrion with 50 people at it, with political leaders involved.”
The archbishop said parents should be trusted to not hold large family gatherings after the ceremonies.
For Archbishop Farrell, it's “not credible” to say a parent bringing their child for communion or confirmation in a Church is a bigger risk than some of the other events currently allowed to take place.
He said families aren’t naive or foolish and are very conscious of their health - so most will follow the public health guidelines and social distancing advice.
He said worship is “inherently safe in itself”, and the sacraments are “being abused in order to influence possible associated family behaviour".
The archbishop added: "For me, that’s deeply problematic.
“It’s doing ultimately is impacting on the freedom of religion - we need to respect that we have a right to practice religion. People are having their rights trampled on or even ignored.”
He added the Government has failed to engage with the Church, "in marked contrast" with the engagement with commercial interests in recent months.