The Mortification Equation

In John Owen's classic work The Mortification of Sin, he states that, "The choicest believers, who are assuredly free from the condemning power of sin, should also make it their business all of their days to mortify the indwelling power of sin."

Then, just a few pages later, Owen asks pointedly, "Do you mortify? Do you make it your daily work? You must always be at it while you live; do not take a day off from this work; always be killing sin or it will be killing you."

So do you mortify? Are you killing your sin, or is your sin killing you?

Now, while we all must acknowledge that all of us can struggle to kill our sin for sinful reasons, I nonetheless find that most sincere believers do ordinarily, by the grace of God, hate their sin and do desire to mortify it. However, what they often lack is the practical knowledge of how to get started with this work in their day-to-day lives.

The rest of this post will seek to help this lack of practical knowledge by presenting one simple, biblical, and practical method for killing indwelling sin, which I've come to call The Mortification Equation.

We see this method put forth in Psalm 119:9-16. There, the psalmist asks, "How can a young man cleanse his way?" Which is to ask, how can a young man mortify his sin? The Psalmist answers, "By taking heed according to your word?" Which is to answer, by taking to heart the word of God and by striving to regulate his head, heart, and hands by it.

That said, the Psalmist then goes on to further explain how a young man can, very practically, take heed according to God's word. The Psalmist continues by saying, "Your word I have hidden in my heart, that I might not sin against You," and later that "I will meditate on Your precepts, and contemplate Your ways."

So the Psalmist teaches us that a very practical way to take heed according to God's word and mortify our sin is by memorization and meditation. By hiding God's word in our hearts and by pondering it in our minds, we are very practically enabled by the Holy Spirit to put our sin to death and to walk more and more in the ways of the Lord.

Consequently, we see then a very practical method, even a kind of equation, for mortification. It is that memorization + meditation = mortification.

Setting Scripture to memory and meditating upon its meaning, purpose, and extent by simply asking basic who, what, when, where, why, and how questions about it is a simple God-given and approved method for killing your sin.

So how can you get started implementing this mortification equation in your own life?

Well, I am glad you asked because while it is not easy (killing something that doesn't want to be killed rarely is!), it can be fairly simple, especially in today's world.

So here is one very practical way to get started mortifying today:

First, identify and target a specific problem sin in your life. Is it using the Lord's name in vain? Is it sinful anger? Bitterness and resentment? Envy? Lust? Love of the world? Laziness? Disrespect? Gossip? Not thinking the best of others? Or something else altogether?

Whatever it is, pick one, and only one at a time, and commit to applying the mortification equation to it.

Second, identify a helpful passage of Scripture that speaks directly to that specific target sin.

For instance, if your target sin is saying the Lord's name in vain, consider Exodus 20:7 or Colossians 3:8.

If it's sinful anger, consider James 1:19-20 or 1 John 3:15.

If it's bitterness and resentment, consider Hebrews 12:15 or Ephesians 4:31-32.

If it's envy, consider Proverbs 1:19 or 14:30.

If it's lust, consider Job 31:1 or 1 Corinthians 6:18.

If it's love of the world, consider John 12:25 or 1 John 2:15.

If it's laziness, consider Proverbs 13:4 or 2 Thessalonians 3:10.

If it's disrespect, consider Exodus 20:12 or 1 Peter 2:17.

If it's gossip, consider Proverbs 16:28 or 17:9.

If it's not thinking the best of others, consider 1 Corinthians 13:7 or Philippians 2:3.

Now, again, you could be struggling with a different sin, and you could use any number of different passages, but the point is to target one specific sin at a time and then identify a specific passage that speaks to it. For help with this, it would be best to talk with your pastor, elders, or a more mature Christian you know and trust, since they will not only know helpful passages for your use but also because they know you.

Third, having targeted a specific sin and having identified a specific passage to combat it, it is now time to set up an ongoing plan for its mortification by intentional memorization and meditation.

For this, a very simple and fruitful plan that I have used and that I have used with others is the following:

Using either your calendar or reminders app on your phone, set three separate daily recurring reminders. For example, one reminder in the morning, one in the afternoon, and one in the evening.

For the first reminder, set it to prompt you to write out by hand whatever passage you have chosen five to ten times. Writing your passage will help you engage more of your senses, and it will slow you down, both of which tend to aid memorization and meditation (see Deuteronomy 17:18-20 for encouragement to write Scripture). For extra help with this part, consider an accountability partner and commit to texting them a picture of your Scripture writing each day, for which they will help keep you accountable.

For the second and third reminders, set them to prompt you to simply recite the passage two to three times in your head, to pray very briefly but sincerely for God to use the passage to kill your sin, and then to ask a single who, what, when, where, why, or how question about your particular passage.

Then, importantly, keep this process going until you begin to see some initial signs of fruit. Often, these initial signs of fruit will involve the Spirit bringing the passage to mind when you need it, along with the grace to take heed according to it.

For instance, if lustful eyes are a specific problem for you and you are using Job 31:1, you will start noticing the passage come to mind at very helpful times, and by the Spirit, you will notice yourself turning your eyes and the eyes of your heart from your sin.

Further, it is important to commit here at this stage to being like Jacob or the persistent widow, and not stop until the Lord blesses, until you begin to see these initial signs of fruit.

Then, after seeing these initial signs of fruit somewhat regularly, you can feel free to change your first reminder from a "write" reminder to a recitation, prayer, and meditation reminder like your second and third reminders.

Next, keep this phase up until you see not just initial signs of fruit, but discernible victory over and mortification of the particular sin you are fighting. Using the example of lust and Job 31:1, this discernible victory might look like an even more frequent calling to mind of the passage, with an even greater ability to turn your eyes, and primarily fewer and fewer instances of even struggling with the sin at all.

Finally, at this point, you can consider moving to just one recitation and prayer reminder per week for that sin and passage, while you then seek to apply the mortification equation to another sin in your life. Keeping the one weekly reminder can help to keep that sin mortified and buried while you move on to another specific and problem sin.

Now, as I said above, though this method and equation for mortification is simple, nothing about it is easy! Mortifying our sin is hard work, and no sure timetable can be set on it. So do not grow weary in well doing!

Moreover, this, of course, is not the only way to fight sin, nor is it a comprehensive plan for every sin in every situation. It is, however, a plan that is almost sure to be helpful, and so it can have a place in fighting just about any sin in your life.

That said, remember, always be killing sin, or it will be killing you. Blessings on your mortifying!