In 1879 in Knock, a small village in County Mayo, Ireland, 15 people coming out of mass witnessed an apparition of the Blessed Mother, St John, and St Joseph, and also present was the Lamb Of God standing on the altar, adored by angels. It was raining and the apparition lasted for approx. 2 hours. It was silent apparition.
The Parish Priest of Knock was just after offering a 100 masses over 100 days for the Holy Souls, and the apparition happened on Day 100. This apparition is therefore attributed to the intercession of the Holy Souls. Ireland had just suffered a horrific famine, where over 1.5 million people died, and over 2 million emigrated. The apparition at Knock gave people hope, and is still visited by over 1 million people each year.
This was after 100 masses were offered up for the Holy Souls This shows us the power of their intercession