“It is indwelling sin that both disenables men unto and hinders them from believing, and that alone. Blindness of mind, stubbornness of the will, sensuality of the affections, all concur to keep poor perishing souls at a distance from Christ. Men are made blind by sin, and cannot see his excellencies; obstinate, and will not lay hold of his righteousness; senseless, and take no notice of their own eternal concerns. Now, certainly that which can prevail with men wise, and sober, and prudent in other things, to neglect and despise the love of God, the blood of Christ, the eternal welfare of their own souls, upon weak and worthless pretenses, must be acknowledged to have an astonishable force and efficacy accompanying it. Whose heart, who has once heard of the ways of God, can but bleed to see poor souls eternally perishing under a thousand gracious invitations to accept of mercy and pardon in the blood of Christ? And can we but be astonished at the power of that principle from whence it is that they run headlong to their own destruction? And yet all this befalls them from the power and deceit of sin that dwells in them.”

(Excerpt from Indwelling Sin in the book Overcoming Sin and Temptation (PDF) by John Owen, p.393)