Yep....fear.

Their criteria of truth contains no logic.
1) They imploy custom as a criterion of truth (knowingly or unwittingly)
2) Tradition ..the notion that it has lasted for generations therefore it must be valid.
3) Time..They appeal that it has withstood the test of time therefore it must be true. The logic of such a statement is based on the assumption that if a belief is really erroneous, the error will sooner or later come to light, whereas, if there is nothing wrong with the belief, the mere passage of time cannot destroy its validity.
4) Feelings (emotions)
5) Instinct...which cannot be accepted as a reliable test. Too often they are vague, ill-defined, and undependable.
6) Intuition...judgement without recourse to reasoning from facts: it is an assumed truth issuing from an unknown or unexplored source.
7) Revelation...The source of revelation is an unknown source...God.

8) Consensus Gentium....anyone and everyone with validity *by THEIR standards* believes it...so therefore it must be true
9) Authority...God is the authority... so it has to be true.