It never occurred to me to question this quote's genuineness because (as I have said) I got this quote from a DEBATE, not some document "issued by CURE." The significance of this is that, at the debate, there was an opposing panel of THREE noted Roman Catholics (Patrick Madrid, VP of Catholic Answers; Robert Sungenis, President of Catholic Apologetics International; and William Marshner, professor of theology at Christendom College, VA) completely ready to pounce on the Protestants' mistakes--and Mike Horton knew this when he gave the quote. Yet after Mike did so, the Catholic panel NEVER brought it up again. It was the PROTESTANT side which had to ask the Catholics about the quote, and their response (as I recall) was to refuse to deal with it. Had Mike been lying or distorting the quote, it would have been a simple matter for the Catholics to point that out or even question the quote's veracity, but they never did. Furthermore, in the 9+ months since the debate, NONE of the Catholics have called back to CURE to accuse the quote of being false!
But since you are 99.99% sure that this quote is bogus, I guess even this will not do. So I called up CURE and asked them for the quote's source--just as you could have, Mr. Core, but obviously chose not to. They gave this to me:
Ratzinger, Joseph: PRINCIPLES OF CATHOLIC THEOLOGY, Ignatius, 1988, page 196.
Contacting Westminister Theological Seminary Library (which yes, Mr. Core, is a Protestant seminary) I was able to obtain access to the book in question and get this quote:
"For nearly half a century, the Church was split into two or three obediences that excommunicated one another, so that every Catholic lived under excommunication by one pope or another, and, in the last analysis, no one could say with certainty which of the contenders had right on his side. The Church no longer offered certainty of salvation; she had become questionable in her whole objective form--the true Church, the true pledge of salvation, had to be sought outside the institution."