My calendar doesn't have any "divine mercy" Sunday.
Anyways, here is an excerpt from the Daily Catholic site:
A local devotion under the title of "Divine Mercy" was approved by the Ordinary of Vilnius in 1936 and from there spread rapidly, especially after World War II in the United States. It appears that Sr. Faustina could not write, save a few lines phonetically. Most of her "diary" was concocted by her sisters after her death. Because of the incongruities of the dairy (different handwriting, different use of terms), the devotion was suppressed, and the book of her diary was placed on the Index Librorum Prohibitorum [Index of Forbidden Books]. This decision was upheld by Pope John XXIII in 1958/59. In early 1978, a Polish cardinal petitioned the Vatican to remove the suppression of the devotion, which was being practiced without sanction in his diocese, and the Vatican replied in the negative, confirming the suppression.
This is the second time I've seen this statement. What gives? This appears to be another manifestation of the traditionalists vs. the "neo-Catholics" debate. From what I can tell, some of the traditionalists are claiming that the Divine Mercy devotion is meant to "replace" devotion to the Sacred Heart, when nothing could be further from the truth. I don't get it.
In early 1978, a Polish cardinal petitioned the Vatican to remove the suppression of the devotion, which was being practiced without sanction in his diocese, and the Vatican replied in the negative, confirming the suppression.
This Polish Cardinal would become Pope John Paul II. What this part of the statement doesn't say is that the "supression" was lifted in 1978 right before Pope Paul VI died. The fact that they don't mention he becomes pope give you a picture to where they are coming from.
What this situation and others in this debate have taught me is to check people's facts.