In an interview with the BBC, the former DUP leader accused the church of having failed to "take a strong stand" on the child abuse scandal and described abusing priests as "anti-Christ".
"We have had a terrible happening in Ireland with the priests and monks and nuns all taking part in acts of disgraceful behaviour with young people, and we haven't seen the Catholic Church taking a strong stand on this," Dr Paisley told the BBC World Service.
"A person, like some of the priests we've had, destroying the lives of young people and then going out and saying 'I can forgive sins', it's only right that be called what it is. That is anti-Christ in teaching and in doctrine."
In March, the pope apologised to victims of abuse by Irish clergy following reports last year which said priests had abused children for decades in Catholic-run institutions, and that church authorities had covered up cases in Dublin until the mid-1990s.
Reiterating his opposition to the forthcoming visit to Britian by Pope Benedict, Dr Paisley described an official invitation extended to the pontiff as "a mistake".
Dr Paisley (84), who stepped down from the post of Northern Ireland first minister in 2008, said the pope should not have been invited for the four-day visit in September during which he will meet the British queen at her official residence in Scotland. It will be the first official papal visit to the country.
"I think it is a mistake," Dr Paisley said, when asked what he thought of the visit. "I think he should not be invited to the country."
Dr Paisley alleged arrangements for the Pope's visit had been made in secret. "You go and ask a question of any minister and he says he doesn't want to have anything to do with it," he added. "The queen is only meeting them on Scottish soil, not on English soil."
The queen is the supreme governor of the Church of England, the mother church of the Anglican Communion. Relations between the CoE and Vatican have been tense after Benedict made an offer to disaffected Anglicans to convert.
Various campaigners plan demonstrations during the pope's visit, including author and atheist campaigner Richard Dawkins who has said he will try to have the pope arrested to face questions over the scandal.
Gay activists are planning protests against his comments on the British government's Equality Bill, while secularists complain at the £8 million bill being picked up by the taxpayer.
SIC: IT