That's a problem that plagues all of us. There are some theoretical things we can say about it, but I'd rather spend time on the practical.
The Roman Catholic Church believes that one function of the church is to be the authorized interpreter of Scripture. They believe that not only do we have an infallible Bible but we also have an infallible interpretation of the Bible. That somewhat ameliorates the problem, although it doesn't eliminate it altogether. You still have those of us who have to interpret the infallible interpretations of the Bible. Sooner or later it gets down to those of us who are not infallible to sort it out. We have this dilemma because there are hosts of differences in interpretations of what the popes say and of what the church councils say, just as there are hosts of different interpretations of what the Bible says.
In an exclusive interview with Reuters, Cardinal Leonardo Sandri, 69, an Argentine, also said the next pope should not be chosen according to a geographic area but must be a "saintly man" qualified to lead the Church in a time of crisis.
He said one of the greatest challenges facing the Church was trying to win back those suffering from a "loss of faith" who had "turned their back on God" and the Church of their fathers.