The Bishop of Elphin, Kevin Doran also claimed "the jury's out" on whether people are born gay.
Speaking to Newstalk radio, when Dr Doran was questioned if he believed being born gay was as God intended, he said: "That would be to suggest that if some people who are born with Down syndrome or Spina Bifida, that that was what God intended either."
Dr Doran also questioned whether gay people in Ireland who already have children could be classed as parents: "They may have children, but that's the point, people who have children are not necessarily parents," he said.
"This legislation that the government is introducing, the Children and Family Relationships Bill, seems primarily focused about making it possible for people in various different relationships to have children. It's not about ensuring that children have their parents," he added.
Ireland's equal marriage referendum takes place on May 22.
