In the highest ranking reaction within the Catholic Church, Cardinal Pietro Parolin - the Vatican secretary of state and one of Pope Francis' closest deputies - today lamented the outcome of the referendum.
Parolin was commenting on the effect the 'Yes' vote is causing within the Vatican when he said he was "sad" at the result.
There is apparent friction among the upper echelons of the Vatican, who campaigned against its approval.
"This result left me feeling very sad but as the Archbishop of Dublin pointed out, the Church will have to take this reality on board in the sense of a renewed and strengthened evangelisation," Cardinal Parolin said in Rome today.
"I believe that we are talking here not just about a defeat for Christian principles but also about a defeat for humanity," he added.
Ireland became the first country in the world to democratically approve gay marriage by popular vote at the weekend. Irish voters backed gay marriage by a wide margin, with 62.1 per cent in favour and 37.9 per cent against.
Parolin's comments echoes those of Archbishop Diarmuid Martin, who spoke of the work the Catholic Church has to do in the future in light of the referendum.
"It is very clear that if this referendum is an affirmation of the views of young people, then the church has a huge task in front of it to find the language to be able to talk to and to get its message across to young people, not just on this issue but in general," he told RTE.