The Catholic Bishop of Waterford and Lismore has said there is "a new culture" trying to "undo the truths" of the Judeo-Christian system by "redefining the meaning of personhood, of marriage, of the family, and classifying people on the basis of their sexual preference".
Bishop Alphonsus Cullinan also said in a pastoral letter to parishioners that this "new culture" is raising individual rights over those of the unborn, and denigrating the sacredness of human life to its natural end.
He also called on parishioners to do all they can to help the church at a time when participation is falling.
The bishop said that about 90% of "our people" are not attending church regularly, "so we must go out 'and seek the lost' (Lk 19:10). If we take a close look at the culture around us we see the great need for God’s grace and our co-operation with that grace.
"There is now a new culture which is trying to undo the truths of the entire Judeo-Christian system from the ground up by redefining the meaning of personhood, of marriage, of the family, and classifying people on the basis of their sexual preference, raising individual rights over those of the unborn, and denigrating the sacredness of human life to its natural end.
"We must wake up to what is happening and, with the grace of God, change the culture from within. If you and I want a culture which is healthy, where family life is helped and supported, where people have hope and can live in freedom to love God and their neighbour as themselves, then we must play our part."
The Diocese of Waterford and Lismore published a pastoral plan last year, aiming to grow involvement in the church, and Bishop Cullinan said he will be visiting parish pastoral councils in the coming months to implement the plan.
Among the objectives was the appointment of a youth ministry officer and a faith development officer, both of whom are due to start work in the autumn.
Already, diocesan ministers are visiting schools and some parishes to speak about their own faith.
"Are you satisfied by what is happening in your parish?", the bishop asks parishioners in his letter.
"Are you happy that young people have so few to minister to them? Are you happy with the way society is going? As a church where are we going? What, as it were, is the sign on the bus? What is the vision?"
Bishop Cullinan said his vision is of a church where people have "a real and living relationship with Jesus; are seeking holiness in their daily lives" and of a church "which, starting from a relationship with Jesus, looks outward rather than inward".