There it was, on the main path to the apparition site of Laus, as one entered what is growing into a major sanctuary: Referring to the seer, Benoite Rencurel, a sign at roadside said, "Part of her ministry was to fight forces of evil."
And so it was and is for Benoite and other visionaries: wherever Mary appears, the Virgin herself once said, there the devil is also.
At Lourdes, dubious and in some cases demonic seers -- a flood of them -- swarmed into the grotto in the midst of Bernadette's legitimate apparitions, all but diluting and in fact extinguishing them.
On her very deathbed, an Easter Monday, Bernadette was heard shouting, "Get out, Satan...! Get out, Satan...!" She confided the next day to the chaplain that "the devil had tried to hurl himself on her, but she had invoked the Name of Jesus and had regained confidence."
It is this battle and how seers handle it -- a battle that often involves temptations and deceptions -- that in the end plays a huge role in whether an apparition is accepted or not. When the devil has an obvious role, the situation is not just rejected, but condemned.
Thus -- in the case of true apparitions -- it is the extent evil is expunged that in large part determines the success or failure of the apparitions.
Many are those sites that due to troubled, misguided, or less-than-exemplary behavior by the seers have fallen by the wayside. In other cases, the devil has directly inflicted harm on the apparitions. Often, the success or lack thereof of an apparition has to do with the seers decision to enter or not enter religious life (for aside from affirming sanctity, religious settings serve as a protection against evil).
Bernadette, of course, became a religious, as did Sister Lucia of Fatima. Both apparitions turned out to be enduring and of massive import. At Fatima, the other two seers (Francisco and Jacinta) died holy deaths as victim souls. In short, all led exceptionally holy lives. (Sister Lucia, though never detailing personal struggles with the evil one, mentioned him several times and said that he was "in the mood" for a final battle in our time. Clearly, she had a sense of his presence.)
The extent to which the devil is expunged seems proportionate to subsequent failure or success. The "Miraculous Medal" maintained a high standard due to the sanctity of Saint Catherine Laboure, a nun who saw Mary there at a chapel in Paris. Apparitions in Kibeho, Rwanda, were accepted after one of the visionaries entered a cloister in Rome. (Though there were seven alleged seers at Kibeho, only she and two others are officially recognized by the Church). On the other hand, the apparition site of LaSalette -- though a highly significant site -- has lacked a similar following not only due to its remote location but also due to controversy which swirled around both seers, neither of whom remained in religious life. Just last week, reports came of Church restrictions, including prohibition of Mass, at another remote, gorgeous setting, Garabandal in Spain, where even the mother of one of the four seers publicly expressed fears that the devil had infiltrated (see the current "special report").
In Wisconsin, an apparition approved in 2010 involved a seer who -- though not technically a religious -- lived as a third-order one (there was no convent or order nearby), and the same was true of Benoite, so holy priests asked her for a blessing as they held vigil at her deathbed. (The result: Laus has total Church approval and is in on its way to major stature. Benoite apparently won many battles.)
There are numerous cases where concerns have arisen over the devil's infiltration.
Many events deemed to have no proof of the supernatural or even demonic may start out authentic but be damaged by the activities or lifestyles. The most visible current circumstance, Medjugorje in Bosnia-Hercegovina, where Mary frequently warned about Satan, is currently under formal Church purview, with no clear indication as yet what effect the seers will have in the permanence of a site that already approaches the size of Fatima.