I've written a lot about the family of Nathaniel Owens and Henrietta (nee Wilson) McIlhagga. Nathaniel was a successful Oil Merchant and they had a large family. What the 1901 Census reveals is that they belonged to The Church of God. One might suspect that such an entry could be a way of avoiding enterning the name of a denomination. However, I think this is probably not so. There is to this day a local church in Conway Street, Shankill, Belfast, called 'The Church of God', which presumably belongs to one of the Pentecostalist denominations. Henrietta certainly started life as a Methodist and Nathaniel probably as a Presbyterian. One son moved from Church of Ireland to Baptist and at least one daughter became a Baptist. In fact, after what is clearly a Pentecostalist 'interlude', by 1911 the whole family is listed as Baptists.
In 1901 there was a John McIlhagga, aged 58 (so born about 1843 in County Antrim) who was a Widower and was boarding with the Graham family in 8 High Street, Ballymena. As far as I know they were not related to him. He was a Presbyterian, as they were, and he worked as a Timber Labourer. His age and occupation are good clues as to whom he was. I think there is only one candidate, John son of William a Weaver from Ahoghill, who married Mary Ann Atkinson on 14th March 1863. They married in the parish church (ie Church of Ireland) of Ballyclug, Ballymena. Clearly Mary Ann had died before 1901. They had had four children, William, John, Elizabeth Jane and Clark. I wrote about these descendants on 9th February in my piece 'Ballyclug to Partick'.
On 14th June I received the following message from Mary in Australia: "I was reading your blog of 11th June where you mention my great-grandparents, James and Jane McIlhagga living at Castlequarter. Castlequarter was the name of the townland at that time, covering Lavin, Ballyportery, Ballyweaney etc. My birth certificate actually gives Castlequarter as the place of my birth. It would be about 7-9 miles from the town of Ballymoney."