Much of Catholicism would be alien to him; Protestantism too. Perhaps it’s best that Patrick is in the past, writes Malachi O’Doherty in today’s Belfast Telegraph.
As a man of the fifth century, Patrick would be appalled and mystified by us all. He might recognise that some of us still wear wool but almost nothing else of us on this island would be familiar to him; not our speech nor our eating habits, let alone our technology.
But were he to sit down with some devoutly religious people and discuss theology he might find some kind of affinity with some of them.
In his day, Mohammed had not yet been born so he might be curious about the tensions between Christianity and Islam.
He would be equally perplexed by some of the Christians claiming that God had been sending Mary, the Mother of Jesus, down to us with messages about the need to revere priests and keep the peace.
It might puzzle him that these visitations had only been happening in the last hundred years or so.
Catholics would be confronted with the paradox that Saint Patrick was oblivious to much that they hold dear. Fatima, Lourdes, Knock and Medjugorje would mean nothing to him.
The doctrine of the Immaculate Conception, by which it is understood that Mary, alone among all humans, was born without original sin, would be something that he would have to discuss a little further before he could decide that he was still theologically tied into the Church of Rome.
And what would he make of the more recent doctrine that Mary never died but that she was assumed bodily into Heaven, from where she returns from time to time?
It is hard to escape the conclusion that so much of what Catholics believe now would be as strange as Islam to Patrick.
It has been argued before that Patrick would probably feel most at home among members of the Church of Ireland.
Well, he would expect Christians here to respect an episcopalian structure, so maybe that is where he would be most at home. But he would not have lived through the Reformation and would wonder how Anglican bishops derived their authority from the Apostles.
How would he respond to the reverence shown by Anglicans to the British monarchy? What would he make of churches that commemorate battles and drape British national flags?
If he was to ask Protestants what it was that they had protested against, would he agree with them?