The Mortification of Sin in Believers

It is the most careful anatomy in English of how a besetting sin actually works, what falsely pretends to cure it, and how it is truly put to death. Owen takes up Paul's clause in Romans 8:13 — that if by the Spirit we put to death the deeds of the body, we shall live — and turns it into a searching, practical handbook for the Christian who is fighting a sin and losing.

Be killing sin, or it will be killing you. It is the line the whole book exists to unfold: that indwelling sin is never dormant or neutral but always at work, so that a believer who ceases the fight will find the fight being carried on against him. The Christian life, on Owen's account, includes a daily, deliberate war that is never finally won this side of death.

It began as sermons to Oxford undergraduates while Owen was vice-chancellor of the university — young men, mostly, who were making no progress against habits they hated. That audience shows: the book is direct, unromantic, and assumes its readers are already trying and already failing, which is exactly why it refuses to hand them more willpower as the answer.

Not the mere restraining of an outward act, nor self-hatred, nor the temporary lull that follows a scare, but the weakening of a sin at its root by the power of the Holy Spirit. Owen is careful to distinguish true mortification from its many counterfeits — a sin merely diverted, or hidden, or aged out of — and insists it is the Spirit's work in which the believer is an active, not passive, participant.

No — and much of the book is spent showing why self-effort, resolutions, and self-loathing are not the same as mortification and cannot do its work. Willpower may suppress a sin's expression while leaving its life untouched. Owen directs the fighter instead to the cross and the Spirit, to faith in Christ and a heart kept tender, as the only power that actually kills sin rather than merely gagging it.

Romans 8:13 — 'if ye through the Spirit do mortify the deeds of the body, ye shall live.' Owen weighs almost every word of it: that the duty is the believer's, that the power is the Spirit's, that the object is the deeds of the body, and that the promise attached is life. The whole treatise is essentially an exposition of that single verse pressed home to the conscience.

No — Owen writes for every believer, because indwelling sin remains in the holiest Christian and the fight is lifelong. He warns particularly against thinking oneself past the danger. The book has been valued across the centuries precisely because it speaks to the ordinary, hidden struggles of serious Christians, not only to dramatic falls.

At the beginning, reading slowly — it is dense but not long. Owen first establishes the necessity and nature of mortification, then exposes the false cures, then gives direction for the actual work. Readers often find the diagnostic chapters, on what mortification is not, the most searching; but the book is meant to end in hope, at the cross where sin is finally undone.