Speaking at a conference, Denis O'Brien urged Church leaders to improve how they communicate with youngsters or risk pushing them away by imposing rules they don't follow.
His recommendation was made to attendees of an event held by the Association of Catholics in Ireland (ACI)which has voiced concerns about the upcoming World Meeting of Families in Ireland, due to be attended by Pope Francis.
O'Brien - who was one of six speaker addressing people who do not strictly follow traditional Catholic teaching - said: "Young people these days...tend not to follow rules that they don't see as valid or sensible.
"For the current youth generation, much of the church's teaching in areas related to sexuality and reproduction is irrelevant and barely rouses their curiosity."
"We should not be afraid of young people's voices. Shutting down discussion, seeking to promote rules that do not seem to make sense and focusing on whether or not something is sinful will drive young people away."
ACI chairman Anthony Neville said he wanted to see a "united church" and one that "accepts the equality of all believers by virtue of their baptism".
"We are conscious of the possibility that at the World Meeting the bishops will present the perfect' Catholic family - mother, father, two children attending Mass every week - and everything in the garden is rosy," he said.
His concerns were reflected by Irene Graham, a divorced mother of five, who had raised her children Catholic.
However, with a gay son, she questioned the Church's teaching regarding homosexuality.
"We want to know when are we going to normalise sexuality - when no one would be looking [at a person] and saying, 'oh he is gay, or she is gay?', she said.
"When will the church say that our sexuality is part of who we are?"
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