In this stirringly honest autobiography, Fr. Ó Madagáin shares his story of how he felt called to serve God and others through the priesthood. He describes his experiences at Medjugorje and Lourdes and how he was moved by the extraordinary sacrifices of individuals both there and in Rome, where he completed his theological education.

By the Word of Their Testimony is no bland endorsement for the vocation of the priesthood, however. Twice Fr. Ó Madagáin suffered burnout caused by both the mental and physical demands placed upon him as a priest. These moments, described in harrowing detail, in turn led him to question not only whether he was suited for the priesthood, but the very nature of faith itself.