John Owen, from his book, Indwelling Sin:
"Many men live in the dark to themselves all their days; whatever else they know, they know not themselves. They know their outward estates, how rich they are, and the condition of their bodies as to health and sickness they are careful to examine; but as to their inward man, and their principles as to God and eternity, they know little or nothing of themselves. Indeed, few labor to grow wise in this matter, few study themselves as they ought, are acquainted with the evils of their own hearts as they ought; on which yet the whole course of their obedience, and consequently of their eternal condition, does depend. This, therefore, is our wisdom; and it is a needful wisdom, if we have any design to please God, or to avoid that which is a provocation to the eyes of his glory."
