"The heart is deceitful above all things, and desperately wicked." Jeremiah 17:9
The deceitfulness of the heart appears in the highest degree, when men overlook the real motives of their conduct, and mistake the workings of their own corruptions, "for the fruits of the Spirit of God.
That there is such deceitfulness in the world, none can doubt, who consider the dreadful enormities that have been committed under the sacred name of religion. In many cases, it must be acknowledged, these enormities have been committed by people who were conscious of the motives from which they acted, and who employed religion merely as an engine to attain the objects of their avarice or ambition. But in other cases it is no less certain, that men have concealed from themselves the motive of their conduct, and even mistaken the workings of their corruptions for the fruits of the Spirit of God.
Men in general, are so backward to acknowledge their faults, and so displeased with those who are so faithful and friendly as to point them out. How few can bear to be told their faults! This is the sure and ready way to make most men your enemies, even though you administer the reproof in the gentlest, and most prudent manner.
Instead of reflecting on their own conduct, which might convince them of the justice of what is laid to their charge, many, in these cases, set themselves immediately to discover the faults in their faithful reprovers, or in those, who, they suspect, may have informed them; and turning away their attention entirely from themselves, are only concerned to find equal, if not greater blemishes in others. Thus deceitful is the heart of man. We wish always to entertain a favorable opinion of ourselves and of our own conduct, and are displeased with those who endeavor in any instance to change this opinion, though it be done with the best, and most friendly intention.
But how unreasonable and preposterous is this degree of self-love! Were we alive to our true interests, we would wish to become better acquainted with our follies and our faults, and would esteem our faithful reprovers our best friends. Instead of feeling any resentment against them, we would turn all our resentment against ourselves; and endeavor, in the strength of divine grace, to correct those evils which, were we not so blinded by self-love, we might easily discover.
But through the deceitfulness of the heart, men are generally disposed to justify their own conduct, and ready to throw the blame of what is amiss on anything else, sooner than on themselves.
David Black, 1762-1806