Perhaps a visit to Lourdes France would help you understand the words of the Blessed Mother.
The Lady says her name: “Que soy era Immaculada Counceptiou”
Le 25 mars 1858, jour de la seizième apparition, Bernadette se rend à la Grotte où, à l’initiative de l’abbé Peyramale, curé de Lourdes, elle demande à “la Dame” de dire son nom. Par trois fois, Bernadette pose la question. A la quatrième demande, “la Dame” lui répond en patois : “Que soy era Immaculada Counceptiou”, ce qui veut dire en français “Je suis l’Immaculée Conception”. Bernadette n’a pas compris immédiatement le sens de cette parole. L’Immaculée Conception, tel que l’enseigne l’Église, c’est “Marie conçue sans péché, grâce aux mérites de la Croix du Christ” (définition du dogme promulgué en 1854). Bernadette se rend aussitôt chez Monsieur le Curé pour lui transmettre le nom de “la Dame”. Il comprend que c’est la Mère de Dieu qui apparaît à la Grotte. Plus tard, l’évêque de Tarbes, Mgr Laurence, authentifiera cette révélation.
http://en.lourdes-france.org/deepen/message-lourdes
On March 25, 1858, day of the Sixteenth apparition, Bernadette goes to the Grotto where, at the initiative of Abbot Peyramale, priest of Lourdes, she asks “the Lady” to tell his name. Three times Bernadette asked the question. At the fourth request, “the Lady” responds in dialect “Que soy era Immaculada Counceptiou” which means in French “I am the Immaculate Conception”. Bernadette does not understand immediately the meaning of this word. The Immaculate Conception, as taught by the Church, is “Mary conceived without sin, through the merits of the Cross of Christ” (definition of the dogma promulgated in 1854). Bernadette goes immediately to the priest to pass it the name of “the Lady”. He understands that it is the Mother of God that appears at the Grotto. Later, Tarbes Bishop Laurence, authenticate this revelation.
That presumes that we accept the purported events at Lourdes to be both true and supported by Scripture. I think it is safe to say that neither of those statements would be true for most Protestants...
Demonic apparitions do not make a good case for anything.