Faith / Knowledge / Doubt

It seems that 'faith', 'knowledge' and 'doubt' are crutial tremini for the metaconcept of 'meaning'. I chose the word 'meaning' over 'truth', because if there is a truth, all we can perceive is probably some kind of abstraction of it.

It's difficult to say how the three words above correlate in particular. Is 'faith' the direct opposite of 'doubt'? Or is 'knowledge' rather more of an opposite to 'faith'? Is 'doubt' an integral part of 'knowledge' or is it contrary?