The cult one can be legitimate if the cult claims to have a source of absolute, no-interpretation-needed, truth and various cult members use it as reason to believe (separately) in P and ~P. While no individual person believes contradictory things, just the fact that the cult’s “absolute truth” can be used to deduce two contradictory things is a sign that it isn’t very good as a source of absolute truth.
The cult one can be legitimate if the cult claims to have a source of absolute, no-interpretation-needed, truth and various cult members use it as reason to believe (separately) in P and ~P. While no individual person believes contradictory things, just the fact that the cult’s “absolute truth” can be used to deduce two contradictory things is a sign that it isn’t very good as a source of absolute truth.