John Owen on the Deceitfulness of Sin

Here are two quotes by John Owen on the deceitfulness of sin. The first observation Owen makes is Christians minimize the full impact of sin.

Solomon tells you of him who was enticed by the lewd woman, that he was "among the simple ones," he was " a young man void of understanding" (Prov. 7:7). And wherein did his folly appear? Why, says he (v. 23), "he knew not that it was for his life," he considered not the guilt of the evil that he was involved in. (p. 97, Overcoming Sin and Temptation)

We should not toy with sin because sin deadens our pursuit and enjoyment of God. The second observation builds on the first observation. Owen solemnly encourages us to be careful and watchful to be not hardened by sin's deceitfulness

This the apostle sorely charges on the Hebrews (3:12-13), "Take heed, brethren, lest there be any of you an evil heart of unbelief, in departing from the living God. But exhort one another daily, while it is called Today; lest any of you be hardened through the deceitfulness of sin." "Take heed, " says he, "use all means, consider you temptations, watch diligently; there is a treachery, a deceit in sin, that tends to the hardening of your hearts from the fear of God." The hardening here mentioned is to the utmost --utter obduration; sin tends to it, and every distemper and lust will make at least some progress toward it. You that were tender, and used to melt under the word, under afflictions, will grow as some have profanely spoken, "sermon-proof and sickness-proof." You that did tremble at the presence of God, thoughts of death, and appearance before him, when you had more assurance of his love than now you have, shall have a stoutness upon your spirit not to be moved by these things. Your soul and your sin shall be spoken of and spoken to, and you shall not be all concerned, but shall be to pass over duties, praying, hearing, reading, and your heart not in the least affected. Sin will grow a light thing to you; you will pass it by as a thing of naught; this it will grow to. And what will be the end of such a condition? Can a sadder thing befall you? Is it not enough to make any heart to tremble, to think ob being brought into that estate wherein he should slight thoughts of sin? Slight thoughts of grace, of mercy, of the blood of Christ, of the law, heaven, and hell, come all in at the same season. Take heed, this is that [which] your lust is working toward--the hardening of the heart, searing of the conscience, blinding of the mind, stupifying of the affections, and deceiving of the whole soul. (pp. 98-99, Overcoming Sin and Temptation)