Although Luisa Piccarreta was strongly endorsed by multiple now canonized saints -- including Pope St. Pius X and St. Padre Pio -- her strongest and most zealous promoter was St. Hannibal di Francia, who became so convinced of the superlative importance of Luisa's mission of the Divine Will (after he was appointed, by the Archbishop, to be her Spiritual Director), that he dedicated the last decades of his life to promoting Luisa's revelations.
Pope St. John Paul II said, regarding St. Hannibal's promotion of Luisa's revelations:
“[St. Hannibal saw] the means God himself had provided to bring about that ‘new and divine’ holiness with which the Holy Spirit wishes to enrich Christians at the dawn of the third millennium, in order to ‘make Christ the heart of the world.’” - Address of His Holiness Pope John Paul II to the Rogationist Fathers. Paragraph 6. 16 May 1997.
St. Hannibal himself said, of Luisa:
“The purest virgin, wholly of God, who emerges to be a singular predilection of the Divine Redeemer, Jesus Our Lord, who century after century, increases ever more the wonders of His love. It seems that He wanted to form this virgin, whom He calls the littlest one He found on earth, and bereft of any education, into an instrument of a mission so sublime that no other can be compared to it—that is, the triumph of the Divine Will upon the whole earth, in conformity with what is said in the ‘Our Father’.” - Hours of the Passion. Introduction. (Also quoted in the Vatican's official biography of Luisa, The Sun of My Will, mentioned above).
Many more teachings of St. Hannibal can be found in his "reflections and practices" he wrote following each hour of Luisa's Hours of the Passion, linked above, as well as in the personal letters he wrote to Luisa.
