Q. Are we required to believe in the apparitions or miraculous appearances of Mary?
Q. What about the Church approved apparitions, like Lourdes or Fatima?
A. No. When the Church approves of an apparition it is not done until the appearances stop. Then all the evidence is examined and if approved it means that we can be assured that there was nothing unorthodox in the revelations and they are worthy of belief. However, these are in the category of private revelation and no one is required to believe them. No matter what is said or who is appearing this information is never anything other than private revelation and is not an addition to doctrine or public revelation.