No more than I had myself before I met Robin, many Catholics have never attended a Church of Ireland service. Protestants don't go to Mass, they go to church. That's because they have different rites of service for different occasions, whereas, on the other side, it's all about the Mass and any "special" events are tagged on to this.
In both churches, basically the same prayers are said, in the same order.
Of course, there are differences, for example, in the pronunciation of Amen. In the Church of Ireland, the "A" is so elongated that I first thought everybody was having their throat examined at the same time.
Other practical differences include no Holy water, no blessing yourself, no genuflection, no purgatory, no special veneration of Mary or other saints. When children are confirmed they begin to receive Holy Communion, with no big deal made about 'First Communion', and, in the Communion, the body and blood are seen as symbols of the body and the blood of Christ rather than actually being them.
Then there are the hymns. As comedian Dara Ó Briain says in a brilliant sketch on the subject: "Protestants, you love the hymns".
In the Catholic Church, many priests now do some singing while there are choirs for special occasions but, outside of those categories, people just don't sing. I am at a loss to know where this comes from. When I was in boarding schools, the Mercy nuns used always say that, when you sing you pray twice.
Of course, there are theological differences, which space and knowledge prevent me from exploring in the current discourse.
Among them are that Protestants place a greater emphasis on a personal interpretation of the Bible and a more direct relationship with God. For example, in terms of confession, you go straight to the man above yourself.
More obvious differences are that women can be priests and that priests can marry.
Some may say that the Catholic Church's stance is all about property and its fear that its asset base would be diluted if priests could marry. But, if that were the case, then surely it would be encouraging gay marriage among its clergy.
I honestly believe that if priests had families themselves, they would have had better understood the evil involved in the sex abuse by some members of the Catholic church over many decades.
Whether or not it's because of the liberty surrounding women and marriage, the shortage of vocations is not as serious in the Church of Ireland though, in common with other Christian religions, it is also struggling to be relevant in today's world.
To many people of whatever belief, one of the few times that religion now crosses our paths is when someone dies. Then we may turn to the Church pretty much as our ancestors did.
Religion cannot change what's happened or always give meaning to the loss, but its rituals may provide families with an outlet for their grief and some solace in their devastation, as witnessed in our own locality last week.
At the end of the day, whether Catholic, Church of Ireland, any other organised religion or none, what matters is not which house you visit on Sunday, it's what you do in your life for the rest of the week.