When my husband suggested we watch Smallville, a TV series on Superman, I was not excited. I like true stories about ordinary people, not made up ones about imaginary people. But to my surprise the first few episodes were fairly normal: a teenage boy living in a small town meets a young billionaire and they become best friends. As one would expect, these two (Clark Kent/Superman and Lex Luthor) would become arch-enemies by the end of the series. However, it takes several seasons to get there; it is only over the span of many years that Clark becomes a hero and Lex becomes a villain.

It turns out that there are more true-story aspects to Superman than I thought. Both Clark and Lex are faced with struggles to overcome and choices to make, each seemingly small, until one day, you realize that one has become a hero and the other a villain. Years ago I was struggling with an indwelling sin that seemed like small, everyday choices, but over the span of many years was leading me down a path I didn’t want to be on. The theologian who helped me get off this path was John Owen, through his book On the Mortification of Sin (i.e., killing sin). Owen argued that since all believers have indwelling sin (that is, sin is dethroned in our hearts but not completely destroyed), fighting sin must be a daily battle for believers. These daily battles, which should result in continual victories though many will be losses, add up over the span of our lives and show who we really are: believers who repent, or unbelievers who do not repent. Just like Clark and Lex, sinful desires are a reality for both, but what is done with these desires is what sets the two characters apart.

Typical for Owen, he has a lot to say. But three big picture ideas have stuck with me over the years and give me motivation to keep saying no to sin:

1. Sin deceives by making you think you are choosing something small and good when you are really choosing something big and bad, even though it might not look like that now

This first point was what really changed my life. I didn’t know my sin had deceived me because that is exactly how sin works. I kept sinning because I didn’t really believe it was wrong. It was difficult for me to start believing what I didn’t believe, because I didn’t believe it! This meant that I would have to trust God more than I trusted myself. Owen explains that sin is very tricky—it starts small and grows slowly, which makes it difficult to detect, but in the end it leads to death. In his words:

“Sin aims always at the utmost: every time it rises up to tempt or entice, might it have its own course, it would go to the utmost sin of 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…it is like the grave, that is never satisfied. And herein lies no small share of the deceitfulness of sin, by which it prevails to the hardening of men, and so to their ruin (Heb. 3:13). It is modest, as it were, in its first motions and proposals; but having once got footing in the heart by them, it constantly makes good ground, and presseth on to some further degrees in the same kind…there is not the best saint in the world but, if he should give over this duty [of mortification], would fall into as many cursed sins as ever any did of his kind”

2. Sin never stops fighting, so neither can you, but the Holy Spirit helps you

Once I believed that I really was sinning and really did need to stop, I felt very depressed about the idea that I had been struggling with this indwelling sin for so long and I despaired of the fact that maybe I would never be free from it. I imagined myself going through each stage of life with this sin and becoming an old woman with a life of regret and pain. But Owen helped me change my perspective. Yes, he said, you will have to fight sin your whole life and it is daunting. In fact, mortification “is a work that requires so many concurrent actings in it, as no self-endeavour can reach unto; and is of such a kind that an almighty energy is necessary for its accomplishment.” Thus, you don’t do it alone. You have the Spirit, and he gives you the energy you need to take on such a big task: “he is the fire which burns up the very root of lust.”

3. Fighting sin actually brings peace and comfort and allows your true self to overcome sin, which is not meant to be a part of you anymore

Once I started to fight more strategically against sin, I saw how much of myself was wrapped up in it. It had become a part of me, and I worried that Jesus’ command to deny yourself was something akin to becoming a robot. However, Owen argues that mortification is not getting rid of yourself, but getting rid of your sin. For example, he says that the Spirit “works in us and upon us as we are fit to be wrought in and upon; that is, so as to preserve our own liberty and free obedience…he works in us and with us, not against us or without us.” In his introduction to Owen’s book, J. I. Packer further describes this as killing the carnal self (which is the “self-will, self-assertion, self-centredness and self-worship, the Adamic syndrome in human nature, the egocentric behaviour pattern, rooted in anti-God aspirations and attitudes, for which the common name is original sin”), not killing the personal self (as if you are “taken over by Jesus Christ in such a way that [your] present experience of thinking and willing would become something different, an experience of Christ himself…animating [you] and doing the thinking and willing for [you]”).

Killing sin does not lead to losing your personhood or your personality, but losing things that are actually ruining who you were created to be. All of the consequences of sin are destructive. Owen describes this as sin weakening and darkening our souls. It weakens our souls in that it “untunes and unframes the heart itself, by entangling its affections,” thus distracting our emotions and taking over our thoughts. It darkens our souls by acting like “a cloud, a thick cloud, that spreads itself over the face of the soul, and intercepts all the beams of God’s love and favour.” It “takes away all sense of the privilege of our adoption; and if the soul begins to gather up thoughts of consolation, sin quickly scatters them.”

Though nothing can separate us from Christ’s love, there is a real connection between sin and condemnation that we cannot deny, and the daily choices we make add up to a life trend of walking by the Spirit or walking by the flesh, which shows who we really are. Every time you succumb to sin it takes a small part of you and if you stay on that road, you will wake up one day as someone you never wanted to be. There is always opportunity to repent and God doesn’t hate his children (he hates their sin), but you might hate yourself and your life might end sooner than you planned.

On the other hand, all of the consequences of mortification are life-giving: it “prunes all the grace of God, and makes room for them in our hearts to grow.” Nothing can make you feel more whole than having peace and comfort from being close to God, and mortification increases these.

I don’t mean to suggest that your whole life should be about your comfort or success, but to show that mortification is actually the better way when it probably seems like the worse way. Your true self is not wrapped up in sin, but being wrapped up in the arms of God. If you feel incomplete and incapable, remember that “God sees it best for us that we should be complete in nothing in ourselves; that in all thing we might be complete in Christ, which is best for us (Col. 2:10).”

Our battle is a lot less glamourous than the ones in Smallville; we don’t have superpowers and we aren’t fighting supervillains. On a daily basis, mortification might look extremely dull, like helping someone you don’t like with something you don’t care about, not losing your patience with your parents, siblings, spouse, or kids, or not gossiping about a girl at school. But the battle against sin is just as significant as Superman’s battle against evil. Owen says, “to know that a man hath such an enemy to deal with, to take notice of it, to consider it as an enemy indeed, and one that is to be destroyed by all possible means, is required hereunto. The contest is vigorous and hazardous; it is about the things of eternity.”

If you’re distraught about a particular indwelling sin, I’d encourage you to read Owen’s book, especially the second half (his “how to” or practical tips for killing sin). You can also find my summary of the book at booksataglance.com by clicking here.