The source of the realization of truth is within man; he himself is the object of his realization

Commentary by Hazrat Inayat Khan:

Men have differed in all ages because they have called their Deity by different names. There have existed wars, fights and family feuds for ages, men dividing themselves merely for the difference of the names they gave to their Deity. Man always sees just what he sees; he cannot see beyond it. With the ideal of his Deity, with the separate names of man's Deities, with all the different attitudes of worshipping his Deity, man remains separate from God, for God is truth and truth is God.
Then the question arises: what is the way to attain the truth? Can it be attained through study? The answer is that the source of realizing the truth is within man - but man is the object of his realization. There are words of Hazrat 'Ali, saying that the one who knows himself truly knows God.