He also said that parishes should acknowledge the LGBT community as part of a parish by mentioning them in homilies or in other presentations; and apologize to them if they have experienced harm from the church.
"You can apologize. It doesn't solve everything, but it's a start," he said.
Martin challenged parishes to advocate for those with same-sex attraction, and to foster a culture of inclusivity.
"By excluding LGBT people, you are breaking up God's family; you are tearing apart the Body of Christ," he added.
"This is part of what it means to be a Christian: standing up for the marginalized, the persecuted, the beaten down. It's shocking how little the Catholic Church has done this."
The priest's presence at the World Meeting of Families caused considerable controversy before he took the stage. Ahead of the talk, more than 16,000 people signed a petition calling for the Jesuit priest to be disinvited from the event.
There were also protests by LGBT groups outside of the complex where the World Meeting of Families is being held. Shortly after Martin spoke, about a dozen members of an LGBT group called the "Rainbow Choir" performed two songs--"Something Inside So Strong" and "We Are Family"--outside of the facility.
Jessica Webbley-O'Gorman, who was with the Rainbow Choir, told CNA that the choir decided to perform after LGBT groups were not permitted to participate in the World Meeting of Families.
Ursula Halligan, an Irish journalist who was one of the organizers of the protest, also questioned the absence of LGBT families from the event. Initially, promotional material for the World Meeting of Families included images of a same-sex couple. These images were later removed.
Prior to the event, the Irish government exerted pressure on the World Meeting of Families, with one government minister warning it should not express "intolerance" of LBGT groups or same-sex couples.
"There should be a welcome for all. And never again should public statements or remarks which seek to isolate certain families be tolerated," said Katherine Zappone, the Irish Minister for Children and Youth Affairs, according to the Irish Times.
Cardinal Farrell responded by saying that the event would revitalize family life and would not exclude anyone.
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"This encounter… is to promote the Christian concept of marriage, and the Catholic concept of marriage, and will focus on that. All people are invited, we don't exclude anybody," the cardinal said.
Christine Rousselle is a former DC Correspondent for Catholic News Agency. Prior to working at CNA, she was the managing web editor of Townhall.com; she has a BA in political science from Providence College.