I have this site, which details the "story" about the lyric by Frederick Faber, the tune by Henri F. Hemy:

http://www.stpaulmerced.com/Site_Music/Faith_of_Our_Fathers/faith_of_our_fathers.html

It has this to say about the lyrics (and I note that anything which refers to Catholic martyrs makes certain culchie types go into an ecstatic trance):

"The "faith of our fathers" referred to in this hymn, however, is the faith of the martyred leaders of the Roman Catholic Church during the sixteenth century. The author of this text, Frederick William Faber, born June 28, 1814, in Calverley, Yorkshire, England, was raised as a strict Calvinist by a father who was an English clergyman. After young Faber's graduation from the renowned Oxford University in 1843, he became a minister in the Anglican Church at a small parish at Elten, England.

In his younger days Faber was strongly opposed to the teachings and practices of the Roman Church. However, this was the time when a movement known as the Oxford or Tractarian Movement was strongly influencing the Anglican Church. Whereas the Wesleys and their evangelical followers preached a message of personal conversion easily grasped by even the illiterate man, leaders of the more sophisticated Oxford Movement were of the persuasion that a meaningful religious experience could only be gained through better liturgical and ceremonial church services. From about 1833 to 1850 the Oxford Movement tenaciously directed religious England, during which time many of the Anglican Church's leaders either joined the Roman Church or developed a rejuvenated high church party known as Anglo-Catholics."