Sin is a bloody business. In the book of Leviticus, the sacrificial system is described in gruesome detail, including what must be done with the blood, fat, and entrails of each animal slaughtered for human sin. It's a book filled with smoke and scent, and a river of blood runs through it: drained, collected, and spattered for the purposes of consecration and purification.

We don't immediately see the relevance of the gore. But maybe the guts are the material point.

Scene of the Crime 

When the worshipper brought his burnt offering to the tabernacle (a bull, sheep, or goat if he could afford it, a bird if he could not), he, not the priest, was responsible to slaughter it. He was implicated physically in the bloody business of sin and atonement. He was, quite literally, at the scene of human crime.

In truth, I do not understand the severity of sin. I appreciate little the holiness of God. Days, like the tide, roll in and out, and I float above the material weight of the gospel: blood was spilled.

Earlier this year I was praying for a renewed sensitivity toward sin—and a deepened appreciation for the Savior. And providentially, I happened upon a book by Puritan preacher John Owen, whose three classic works on sin and temptation have been modernized by Crossway and published under the title Overcoming Sin and Temptation. In Owen, I found language for the Christian's bloody business of killing sin: mortification. It is also the language of the apostle Paul. 

Kill or Be Killed 

If ye through the Spirit do mortify the deeds of the body, ye shall live. (Rom. 8:13, KJV)

Owen provides much practical wisdom on how to “mortify,” or put to death, the deeds of the flesh. Here are a few points that stuck with me.

Be killing sin, or it will be killing you. Owen warns there is no neutrality in our spiritual lives. If there is not advancement against the enemy, there is retreat: “Let no man think he makes any progress in holiness who walks not over the bellies of his lusts.” Owen takes pains to expose the ways in which sin is deceitful (Heb. 3:13). As an example, sin will always be “modest . . . in its first motions and proposals.” We are easily duped into believing that our sins are only small infractions, slight indiscretions. But this deception permits greater compromise: “Sin aims always at the utmost; every time it rises up to tempt or entice, might it have its own course, it would go out to the utmost sin in that kind. Every unclean thought or glance would be adultery if it could; every covetous desire would be oppression, every thought of unbelief would be atheism, might it grow to its head.”

There is nothing benign about sin, no matter how small or slight it might initially seem; every sin is a cancer that will multiply and kill. Be killing it instead.

Lay your axe at the root, drive still at the heart. The sin, with which we should be must troubled, is not the sin of evil behavior, but the sin of disordered desire. It is a futile and foolish exercise to pluck the fruit of sin without excavating the root. Such measures grant temporary change, but they do not sustain lifelong transformation: “He that changes pride for worldliness, sensuality for Pharisaism, vanity in himself to the contempt of others, let him not think that he has mortified the sin that he seems to have left. He has changed his master, but is a servant still.” Our fight against sin must be leveled at the heart, whose plague, Owen calls it, we must know (1 Kings 8:38).

As Jesus said, we must be as serious about hatred as we are with murder, as diligent about lust as we are with adultery. Without attentiveness to the sins of the heart, we are in danger of becoming whitewashed tombs (Matt. 5:21-30, 23:25-28). Only redeemed desire seeds true holiness.

Hatred of sin as sin lies at the bottom of all true spiritual mortification. Owen challenges us to hate sin universally—not simply the sin that troubles us. It is easy to hate the sin that causes pain. We want to be rid of our anger for the health of our family. We want be rid of our laziness for the sake of godly productivity. We want to be rid of our gluttony for the sake of our waistline. But what about the sin that fails to trouble us? What about the sin whose patterns have become so convenient, whose outcomes have become so reliably comforting? What about the pleasures we find in our lust and greed? “He, then, that would really, thoroughly, and acceptably mortify any disquieting lust, let him take care to be equally diligent in all parts of obedience, and know that every lust, every omission of duty, is burdensome to God (Isa. 43:24), though but one is so to him.” 

We must hate sin as sin because “[God] is grieved by our harboring his enemies.”

There is no death of sin without the death of Christ. In our fight to mortify the flesh, we can attempt measures of self-control—“vows, penances,” as Owen refers to them—but sin does not die apart from the cross of Jesus Christ. Sin is a bloody business, and it is Jesus's blood, not the blood of bulls and goats, that has made the perfect sacrifice for its remission. We mortify our flesh when we remember his sacrifice. The book of Hebrews makes explicit connection between the ministry of Jesus and the Old Testament sacrificial system as described in Leviticus. Jesus is the priest (Heb. 2:17), and Jesus is the sacrifice (Heb. 9:12). As he stood at the entrance of the heavenly tabernacle, he did not bring a bull or goat. Though morally guiltless, he offered himself. It was the innocent blood of Jesus that was drained, collected, and spattered for the final work of atonement.

Even after more than a month of dedicated mortification, I fear I yet suffer the condition, which Owen calls “inveterateness.” I am easily deceived by sin. I am hardened to its seriousness. But perhaps daily, as a lifelong practice, I can preach this material gospel of guts and thank God for his indescribable gift (2 Cor. 9:15).