The Father of the Church tell us that the sufferings endured by the souls in Purgatory are terrible to the extreme. According to St. Cyril, Patriarch of Alexandria, it would be preferable to suffer all imaginable anguish to the End of Time than to pass one day in Purgatory.
There are many different ways of helping the suffering souls and delivering them from Purgatory, but none of these is so sure and so effectual as the Holy Sacrifice of the Mass. The Church, speaking by the Council of Trent, declares this to be the case: "This Ecumenical Synod teaches that the souls detained in Purgatory are helped by the suffrages f the Faithful, but principally by the acceptable Sacrifice of the Altar." (Sess. xxv). This is laid down as an article of faith, which no man can gainsay. The same was asserted two centuries previously by the Angelic Doctor, St. Thomas Aquinas: "By no other oblation can the souls in Purgatory be more speedily released than by the Sacrifice of the Mass."
- The Incredible Catholic Mass by Fr. Martin von Cochem
Nocturnal Adoration Society Letter November 2010