A little prayer book I have called Pieta contains a letter alleged to have been written by the Blessed Virgin Mary (page 17). Is this a true letter written by the Blessed Virgin Mary?
Not likely. At best, it may be a private revelation some person believed he or she was given by the Blessed Virgin Mary and was later confused for an actual letter. In any case, as an unapproved private revelation it is not incumbent on any Catholic to believe its authenticity. Even if it were a letter of the Blessed Virgin Mary, it could not be considered on par with sacred Scripture.
Recommended reading:
What If We Found a New Letter of Paul? (Part 1, Part 2) by Jimmy Akin
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