“Extinguish not the spirit. Despise not prophecies. But prove all things; hold fast that which is good.” (1 Thes 5:19-21)
The Catholic teaching on private revelation boils down to these basic points:
All that the Father desired to reveal for our salvation has been revealed in His Word, Jesus Christ. This is known as the Deposit of Faith. Private revelations do not belong to the Deposit of Faith.
Private revelation may help us live more fully by Christ’s Revelation during a certain period of history, but must never presume to alter Christ’s definitive Revelation.
The Catholic Church investigates private revelations that gain enough of a following to become potentially problematic for the faithful. Three outcomes are possible:
1. The Church will withhold judgment.
E.g., Medjugorje, which is still on-going, is in this area. While the Church has not condemned the visions or suppressed discussion of Medjugorje, recent statements from the Vatican have been highly cautionary, not because there has been anything problematic to the Deposit of Faith, but because none of the events has risen to the very high level of “definitely supernatural AND from God” which is required by the Church.
Colin B. Donovan, STL, writes that as of 2013: “Catholics on both sides of the issue should exercise prudence and charity in speaking of it. Medjugorje is not a litmus test of orthodoxy, though every Catholic will have a moral obligation to accept the judgment of Rome when it is rendered.”
2. The Church will condemn the revelation.
An example of such a condemnation comes from the Bishop of Brooklyn concerning the alleged apparitions at Bayside: “A thorough investigation revealed that the alleged ‘visions of Bayside’ completely lacked authenticity. … The ‘messages’ and other related propaganda contain statements which, among other things, are contrary to the teachings of the Catholic Church, undermine the legitimate authority of bishops and councils and instill doubts in the minds of the faithful, for example, by claiming that, for years, an ‘imposter (sic) Pope’ governed the Catholic Church in place of Paul VI.”
3. The Church will declare the revelation “worthy of belief.”
For example, the visions of Fatima, Portugal, were declared worthy of belief in October 1930 by the Bishop of Leiria-Fátima. Approved private revelations do not become a part of the Deposit of Faith, thus Catholics are not bound to believe in them. However, such refusal must be done with proper modesty, for good reasons, and without the intention of setting oneself up as a superior.
EXCELLENT overview: “Apparitions/Private Revelations” article by Colin B. Donovan, STL, at EWTN @ https://www.ewtn.com/expert/answers/apparitions.htm
Catholic Catechism on Private Revelation @ http://www.vatican.va/archive/ccc_css/archive/catechism/p1s1c2a1.htm
Dei Verbum (Dogmatic Constitution on Divine Revelation) @ http://www.vatican.va/archive/hist_councils/ii_vatican_council/documents/vat-ii_const_19651118_dei-verbum_en.html
Declaration concerning the “Bayside Movement” by Bishop Francis Mugavero of Brooklyn- November 4, 1986 @ http://www.ewtn.com/library/newage/mugabay.txt
Official position of the Catholic Church on the Fatima apparitions @ http://en.wikipedia.org/wiki/Our_Lady_of_F%C3%A1tima#Official_position_of_the_Catholic_Church
Historical overview of the Catholic Church’s evolving position on Medjugorje apparitions by Colin B. Donovan, STL @ https://www.ewtn.com/expert/answers/medjugorje.htm