The reason why so far nothing has been done regarding the publication of the “third secret” is not at all because the popes would want to hide something terrible. From Fatima an earnest signal was sent out, addressing the prevailing thoughtlessness, a reminder of the seriousness of life and of history, and pointing to the perils threatening all mankind. It repeats what Jesus himslef quite often warns about when he without hesitation says, “Unless you repent you will all perish” (Lk 13:3).
Repentance – as Fatima remind us so vividly – is a constant challenge for the Christian life. This we should already have learned from all of Sacred Scripture. Our Holy Father has concluded that nothing new would be added to those things that a Christian should know from revelation, and also from Mary’s apparitions, acknowledged by the Church, and their messages, which confirm the urgency of repentance, conversion, forgiveness, and fasting.
If the “third secret” were to be published, there would also be the danger that its content might simply be misused for sensationalism. No apparition at all is indispensable for the Faith; revelation was completed with Jesus Christ. He himself is the revelation. Of course, we could certainly never dare to hinder God from speaking to this our time through lowly persons as well as through extraordinary signs, which show us how wanting are the cultures that dominate us, as they are determined by rationalism and positivism. The apparitions officially recognized by the Church – especially Lourdes and Fatima – have their clearly defined place within the development of the Church’s life in the past century. Not least of what they demonstrate is that revelation – despite its being unique, complete, and therefore unsurpassable – is never something dead but is always living and dynamic.
From: Zur Lage des Glaubens, pp. 111f.