I'm beginning to believe my great grandmother Mary converted from her Catholic religion to marry my great grandfather John Joseph...who was a member of the Church of Ireland religion...her fathers name was name was Patrick, could she have lied about his name, saying Stephen as if she said her father's real name, an instantly recognisable Catholic name, they would have raised an eyebrow in that church they were married in? This was 1925 after all
I don't buy that scenario.
Did the Church of Ireland require both parties to a marriage to be baptised members of C. of I in 1925? Current regulation is that at least 1 party "shall have been baptised and is a member of C. of I. or of a Church in full communion therewith, unless in exceptional circumstances, the bishop shall determine otherwise." I assume it was the same in 1925.
What evidence do you have that your great-grandfather was C of I.?
Are you certain that the marriage in Dublin in 1925 was that of your great-grandparents?
https://www.irish-geneaography.com/hunting-for-irish-marriages.htmlYou said previously that the story in your family was that a Catholic priest refused to marry them. That seems more plausible if only one of them was R.C.
The Catholic Church became stricter about marriage in the early decades of 20th century. "Ne temere" decree on marriage (1907, effective from Easter 1908)) required marriages involving a Catholic to take place in the bride's parish, in the presence of a Catholic priest and that the marriages be recorded in the place/places where the contracting parties were baptised. The Code of Canon Law was set out and published by the Catholic Church in 1917.
A wedding of a Catholic and someone who wasn't Catholic in a Catholic church would require a dispensation. The priest had to be confident that the Catholic spouse would still be able to practise their faith and that children of the marriage would be brought up in the faith. The non-Catholic party had to agree to those requirements if the marriage was to happen in a Catholic church.