We have studied the very large amount of literary works written by the Italian mystic Maria Valtorta to assess similarities and differences in her writings, because she claims that most of them are due to mystical visions. We have used mathematical and statistical tools developed for specifically studying deep linguistic aspects of texts. The general trend indicates that the literary works explicitly attributable to Maria Valtorta differ significantly from her other literary works, which she claims are attributable to the alleged characters Jesus and Mary. Mathematically, they seem to have been written by different authors. The comparison with the Italian literature is very striking. A single author, namely Maria Valtorta, seems to be able to write texts so diverse as to cover the entire mathematical range (suitably defined) of the Italian literature spanning seven centuries.We have used mathematical and statistical tools developed for specifically studying deep linguistic aspects of literary texts, such as the readability index, the number of characters per word, the number of words per sentence, the number of punctuation marks per sentence and the number of words per punctuation marks, known as the word interval, all peculiar to a writer's style. Our innovative approach allows assessing, from a probabilistic point of view, similarities and differences in her many different writings. Our findings show that she has written so radically diverse texts, mathematically speaking, that, as shown in the following, no author has been able to do in seven centuries of Italian literature.