Ven. Nyanatiloka Thera (Buddhist Dictionary); Wisdom Quarterly
Beautiful FAKE Buddha quote, which should say "Question everything and be a lamp unto yourself to work out your own salvation from samsara, rebirth, and suffering (Stratoz).
How can I ever be sure? - Noble insight!
"Doubt" (kankhā) may be either an intellectual and critical doubt or an ethically and psychologically detrimental doubt.
The latter may either be a persistent negative skepticism or weak wavering indecision. Only the detrimental skeptical doubt (identical with vicikicchā) is to be rejected as karmically unwholesome, as it paralyzes thinking and hinders the inner development of a person.
Reasoned, critical doubt in dubious matters is thereby encouraged.
The 16 doubts enumerated in the sutras, for example in the Middle Length Discourses (MN 2), are the following difficult to ponder questions:
And another question, Where will we eat?
"Have I been in the past [past lives]?
Or have I not been in the past?
What have I been [when I was reborn] in the past?
How have I been in the past?
From what state into what state did I change in the past?
Shall I be in the future?
Or shall I not be in the future?
What shall I be in the future?
How shall I be in the future?
From what state into what state shall I change in the future?
Am I?
Or am I not?
What am I?
How am I?
How have I come into being
Where will I go?"