Rorate Caeli has released a translation of a remarkable interview, originally published in 2008, with Cardinal Carlo Caffarra of Bologna. In it, he references correspondence he had with Sister Lucia, the principal visionary of Our Lady at Fatima:

Q. There is a prophecy by Sister Lucia dos Santos, of Fatima, which concerns “the final battle between the Lord and the kingdom of Satan”. The battlefield is the family. Life and the family. We know that you were given charge by John Paul II to plan and establish the Pontifical Institute for the Studies on Marriage and the Family.

>Yes, I was. At the start of this work entrusted to me by the Servant of God John Paul II, I wrote to Sister Lucia of Fatima through her Bishop as I couldn’t do so directly. Unexplainably however, since I didn’t expect an answer, seeing that I had only asked for prayers, I received a very long letter with her signature – now in the Institute’s archives. In it we find written: the final battle between the Lord and the reign of Satan will be about marriage and the family. Don’t be afraid, she added, because anyone who operates for the sanctity of marriage and the family will always be contended and opposed in every way, because this is the decisive issue. And then she concluded: however, Our Lady has already crushed its head.

Talking also to John Paul II, you felt too that this was the crux, as it touches the very pillar of creation, the truth of the relationship between man and woman among the generations. If the founding pillar is touched the entire building collapses and we see this now, because we are at this point and we know it. And I’m moved when I read the best biographies of Padre Pio , on how this man was so attentive to the sanctity of marriage and the sanctity of the spouses, even with justifiable rigor on occasion.