Do you mortify; do you make it your daily work; be always at it whilst you live; cease not a day from this work; be killing sin or it will be killing you.Of the Mortification of Sin in Believers Chapter 2
That is why the unregenerate person cannot understand the urgency of the gospel message: until they see the depth of their sin and the holiness of God, they find no reason to seek remedy for their condition.
When I turn to the map of the world I must say the same thing. It matters not what quarter I examine: I find men's hearts are everywhere the same, and everywhere wicked. Sin is the family disease of all the children of Adam.Old Paths, Ch 7
You can never part with sin soon enough; it is a cursed inmate, that will surely bring mischief upon the soul that harbours it. It will set its own dwelling on fire.Works 7:147
At the heart of all sin is a lie. The lie says to all of us in our sin, "The act you are now doing, the desire or attitude you are now feeling is not very bad because there are much worse things, not very bad because everyone else experiences the same things, not very bad because you can't help it, not very bad because there is no God, or, if that won't work, God knows you are but frail and weak and he will tolerate and pity your sin." There are a thousand distortions of the truth which sin brings with it into the human heart, so that Jeremiah cries out, "The heart is deceitful above all things and desperately corrupt; who can understand it?" (17:9).
Resolved, when I am most conscious of provocations to ill nature and anger, that I will strive most to feel and act good-naturedly; yea, at such times, to manifest good nature, though I think that in other respects it would be disadvantageous, and so as would be imprudent at other times.https://www.desiringgod.org/articles/the-resolutions-of-jonathan-edwards
How monstrous a thing is rebellion! How direful a doom is prepared for the ungodly! My soul, never laugh at sin's fooleries, lest thou come to smile at sin itself. It is thine enemy, and thy Lord's enemy. View it with detestation
The fallen condition of all humankind in Adam is not the result of mere social conditioning but is such "by nature" (φύσει, physei)Ephesians, Evangelical Exegetical Commentary (Bellingham, WA: Lexham Press, 2015), 152.