We consider the Divine Mercy devotion, the indulgence offered by the Church, and also the promise which our Lord made for Divine Mercy Sunday.We then show that this Sunday (especially before Vatican II) has always been perfect for the Divine Mercy Devotion, and that Divine Mercy Chaplet largely come from the Traditional Good Friday commemoration of the Passion.  Any who love the TLM should love the Divine Mercy Devotion, and those who love the Divine Mercy Devotion should love the Tridentine rites!Listen online [here]!