God gave us an infallible authority on Earth so we can know the truth, and that authority is the pope, who is always right. Except when he's not. And you can tell which he is because a later pope or church council informs you of which he was. Unless an even later church council says that particular church council is wrong, usually after an even later pope says the previous later pope erred. And we know the later-later pope is actually correct because there isn't yet a later-later-later pope than this current-later pope who corrected the later pope that verified/refuted the original pope. And there is no later-later-later council to dispute either current-pope or current-council, since the later-later-council hasn't been formed yet either.
How could anyone get more certainty than from this process?