In one of his talks in The Hermeneutics of the Subject, Michel Foucault explores the question of truth from the perspective of spirituality. I find it interesting:
"Spirituality postulates that the truth is never given to the subject by right. Spirituality postulates that the subject as such does not have right of access to the truth and is not capable of having access to the truth. It postulates that the truth is not given to the subject by a simple act of knowledge, which would be founded and justified simply by the fact that he is the subject and because he possesses this or that structure of subjectivity. It postulates that for the subject to have right of access to the truth he must be changed, transformed, shifted, and become, to some extent and up to a certain point, other than himself. The truth is only given to the subject at a price that brings the subject's being into play. For as he is, the subject is not capable of truth...
Finally, spirituality postulates that once access to the truth has really been opened up, it produces effects that are, of course, the consequence of the spiritual approach taken in order to achieve this, but which at the same time are something quite different and much more: effects which I will call "rebound" ("de retour"), effects of the truth on the subject. For spirituality, the truth is not just what is given to the subject, as reward for the act of knowledge as it were, and to fulfill the act of knowledge. The truth enlightens the subject; the truth gives beatitude to the subject; the truth gives the subject tranquility of the soul. In short, in the truth and in access to the truth, there is something that fulfills the subject himself, which fulfills or transfigures his very being.
In short, I think we can say that in and of itself an act of knowledge could never give access to the truth unless it was prepared, accompanied, doubled, and completed by a certain transformation of the subject; not of the individual, but of the subject himself in his being as subject."