Was St. Patrick a good Catholic? Most would say that you might as well say is the Pope Catholic! But often truth is indeed stranger than fiction, or even green beer.
Many of the tales and lore associated with St. Patrick come from Tirechán’s LIfe of Patrick, which was written about 700 A.D., or roughly 250 years after Patrick’s death. Unfortunately Tirechán’s book is not only completely revisionistic but also primarily fictitious. Tirechán’s work mostly reflects the priorities of an 8th century Catholic hierarchy who were at that point desperately trying to claim Patrick’s missionary legacy as their own in their campaign to pressure the remainder of the stubbornly independent Celtic Christian congregations in Ireland who were refusing to “enter into unity with Rome,”
Far from being a part of the Roman hierarchy, Patrick of Ireland ran a self-funded independent ministry. He never answered to Rome’s direction. Patrick was a part of the 5th to 7th century Celtic Christian movement in the British Isles, which followed a decentralized form of church organization. Deliberately maintaining isolation for over 150 years from the Catholic form of Christianity on the continent, the Celtic Christians of Britain and Ireland steadfastly refused to obey the Roman church’s hierarchy either administratively or doctrinally, according to York University professors Michael W. Herren and Shirley Ann Brown in their book Christ in Celtic Christianity.
It’s noteworthy that Patrick’s own grandfather, a married Christian priest, and his father, a married Christian deacon, did not buy into the Catholic Church’s Augustinian theology about original sin and infant baptism. Patrick’s family did not baptise him as a baby, according to Patrick’s own testimony. Rather Patrick’s family followed the theology of Pelagius, Augustine of Hippo’s theological nemesis. Pelagius taught that Adam’s sin at the Garden of Eden did not result in human nature becoming utterly depraved and, consequently, sexual intercouse did not transmit Augustine’s fictitious “original sin.” (This was the origin of the “sex is evil” idea in Catholicism.) Consequently, baptism, according to Pelagian theology, was only for those with mature minds who could fully appreciate the level of commitment required from one who repents of a sinful lifestyle.
Leslie Hardinge in his book The Celtic Church in Britain notes that unlike the strongly anti-Semitic 
attitudes held by the Roman church, the Celtic Christian churches strongly valued their faith’s Hebrew roots. Accordingly, the Celtic Christians held their Pascale (Passover) ceremony of taking the Lord’s Last Supper with the bread and the wine on “the 14th moon” (Nisan 14 on the Hebrew calendar) rather than following the Roman churches calculations based on the pagan Roman Julian calendar. The Celtic Christians continued to “remember the Sabbath to keep it holy” on the 7th day of the week, which the Roman Christians did not.
Hardinge also writes, “Wherever Patrick established a church he was believed to have left a copy of the books of the Law and the Books of the Gospel. The Leber ex Lege Moisi is the only work surviving from Celtic sources which answers to the description “books of the Law.” Each of the four extant manuscripts of this work has an Irish provenance. The earliest has been dated about 800, and had apparently been copied from an earlier manuscript. It commences with the Decalogue and contains selections from the Books of Exodus, Leviticus, Numbers, and Deuteronomy, which are filled with citations from the Old Latin.” (Hardinge, pp 49-50).
Such a practice clearly reveals that Patrick had a strong “Scripturalist” approach to his religious understanding. The Scriptures were his authority. According to Profs. Herren & Brown to be a Scripturalist was typical of the Celtic Christian movement but radically atypical of those who supported the bishops of Rome and their hierarchy.
It would appear from the evidence that Patrick of Ireland would not have been considered by his early Medieval contemporaries to be a “good” Catholic. Even the foremost Catholic church historian of the British Isles of the early Medieval era, Bede, knew nothing about a “St. Patrick.” In this case, the truth is indeed stranger than fiction or even green beer. Cheers!
