The central point of chapter 4 is that the "life, vigor, and comfort of our spiritual life depends much on our mortification of sin". As I read this I thought a fitting backdrop would be Edwards' 22nd resolution: "Resolved, to endeavor to obtain for myself as much happiness, in the other world, as I possibly can, with all the power, might, vigor, and vehemence, yea violence, I am capable of, or can bring myself to exert, in any way that can be thought of." If we are resolved like Edwards (or Piper after him) to pursue as much happiness in God as possible then we can learn from Owen that this comes from mortification of sin.
Owen does an excellent job of reminding us that the gift of "life, vigor, and comfort" do not come from mortification but they are fruits of our adoption and justification. But I think Owen is saying that if we are to pursue such joy (as Edwards spoke of) then it will come not only from our adoption and justification but also from our mortification of sin. Sin will do two things, says Owen: "It will weaken the soul and deprive it of its vigor. It will darken the soul and deprive it of its comfort and peace." Owen then launches into a gut-wrenching discussion of all that unmortified sin results in:
- It weakens the soul and deprives it of its strength
- It untunes and unframes the heart itself by entangling its affections
- It fills the thoughts with contrivances about it (in other words the flesh fills itself with thoughts about the flesh and how to gratify its desires, setting you on a downward spiral)
- It breaks out and actually hinders duty
- As sin weakens so it darkens the soul (As Owen says, "It intercepts all the beams of God's love and favor")
Owen then closes with a beautiful analogy of a garden:
Now, as you may see in a garden, let there be a precious herb planted, and let the ground be untilled, and weeds grow about it, perhaps it will live still, but be a poor, withering, unuseful thing. You must look and search for it, and sometimes can scarce find it; and when you do, you can scarce know it, whether it be the plant you look for or not; and suppose it be, you can make no use of it at all. When, let another of the same kind be set in the ground, naturally as barren and bad as the other, but let it be well weeded, and everything that is noxious and hurtful removed from it—it flourishes and thrives; you may see it at first look into the garden, and have it for your use when you please. So it is with the graces of the Spirit that are planted in our hearts. That is true; they are still, they abide in a heart where there is some neglect of mortification; but they are ready to die (Rev. 3:2), they are withering and decaying. The heart is like the sluggard’s field—so overgrown with weeds that you can scarce see the good corn. Such a man may search for faith, love, and zeal, and scarce be able to find any; and if he does discover that these graces are there yet alive and sincere, yet they are so weak, so clogged with lusts, that they are of very little use; they remain, indeed, but are ready to die. But now let the heart be cleansed by mortification, the weeds of lust constantly and daily rooted up (as they spring daily, nature being their proper soil), let room be made for grace to thrive and flourish—how will every grace act its part, and be ready for every use and purpose!As I think about this chapter I am struck with how stupid it is to let sin dwell within us. It does such damage; yet I continue to see its effects daily. I find myself at times caving in to its pullings and inevitably I experience what Owen says happens--a deadness of spirit. This chapter encourages me to run to the Cross at the least hint of sin and thereby seek its mortification.