Jonathan Edwards on Spiritual Pride

Jonathan Edwards found human language almost inadequate to express the insidious nature of spiritual pride. It would take several metaphors even to begin describing this strategy of Satan. “This is,” he wrote, “the main door by which the Devil comes into the hearts of those who are zealous for the advancement of religion. ‘Tis the chief inlet of smoke from the bottomless pit, to darken the mind, and mislead the judgment; this is the main handle by which the Devil takes hold of religious persons, and the chief source of all the mischief that he introduces, to clog and hinder a work of God. This cause of error is the mainspring, or at least the main support of all the rest. Till this disease is cured, medicines are in vain applied to heal all other diseases.”
Later, he writes:

There is no sin so much like the Devil as this, for secrecy and subtlety, and appearing in great many shapes that are undetected and unsuspected, and even appearing as an angel of light: it takes occasion to arise from everything; it perverts and abuses everything, and even the exercises of real grace and real humility, as an occasion to exert itself.

It is a sin that has, as it were, many lives; if you kill it, it will live still; if you mortify and suppress it in one shape, it rises in another; if you think it is all gone, yet it is there still.

There are a great many kinds of it, that lie in different forms and shapes, one under another, and encompass the heart like the coats of an onion; if you pull off one, there is another underneath.

We had need therefore to have the greatest watch imaginable, over our hearts, with respect to this matter, and to cry most earnestly to the great Searcher of hearts, for his help. “He that trusts his own heart is a fool” [Prov. 28:26]

—Jonathan Edwards, “Some Thoughts Concerning the Present Revival of Religion in New England,” in The Great Awakening, ed. C. C. Goen, The Works of Jonathan Edwards, vol. 4 (New Haven: Yale University Press, 1972), 414, 416-417.
“Who will deliver me from this body of death? Thanks be to God through Jesus Christ our Lord! (Rom. 7:24-25)