There was a time when Ireland was seen as a staunchly Catholic country with plenty of religiosity on show. However, religious observance and interior spirituality are very different things and the ongoing drift away from Catholicism may be a manifestation of this.
What brought this to mind is that the main subject of this photo, St. Pauls's Church, is no longer a parish place of worship. Population changes also may be part of this and the building now sees use by a Catholic youth group and the St. Gregrorios Jacobite Syrian Christian Church.
The building remains architecturally significant since it is one of those designed by Patrick Byrne in the Greek Revival style. It also was where Eamon and Sinead De Valera married in 1910 while Captain Charles Boycott married Annie Dunne there in 1852 so the place also has its share of history. In some ways, it is as significant a landmark as the Four Courts, which can be seen further along the riverside above.