Psychology is no substitute for the gospel, but we wouldn’t be beating spears into pruning-hooks if we weren’t mining the field of psychology for reasons to praise God. Of course, the inerrant Word of God is bigger bang for your buck, and handling psychology without a Biblical theology will surely lead to absurdity! But Calvin’s maxim is still true if the psychology we learn is actively shaped and molded by a Biblical theology: “Our wisdom, in so far as it ought to be deemed true and solid Wisdom, consists almost entirely of two parts: the knowledge of God and of ourselves.”
Psychology is a tool that can help us learn about ourselves and God when examined under the authority of God’s Word. On that note, one interesting fossil modern researches are returning with from the field of Psychology is called ego depletion. The gospel-centered movement has radically re-shaped my relationship with Jesus in many ways, and one of those ways has been the instruction of focusing less on religious to-do lists and more on good news. This last sentence was not disjointed from the idea of ego-depletion; permit me to write on the confluence of the two!
Ego depletion is the theory that attributes like willpower are highly overrated. Certainly willpower and the like are good characteristics to possess; Galatians teaches us that self-control is a bite of the fruit of the Spirit! But if these are good characteristics to possess, then what makes them overrated? According to psychologists, it’s because these attributes have very finite reservoirs. Think of it this way: each time you draw from the well of self-control, the next time you return there will be less waiting for you. Again, think of any physical bucket of water: with any removal of water there remains less water in the bucket for you when you return. Unfortunately, your self-control in its fallen state operates the same way. Depletion: simple enough. But what does this have to do with Christianity? I might contest it informs the way we shepherd our people towards God and away from sin.
In short, this means that the victory over the fight against sin is not at root due to the muscle of self-control. Or, in other words, a hatred for our sin is not strong enough to resist sin. Perhaps we will be able to resist sin when the tongue first begins to salivate. But our act of resistance will be like a bucket of self-control drawn from our well. Perhaps even we will be able to resist sin when the hand first begins to shake. Even still, a bigger bucket of self-control is drawn from our well, and then, what are we left with? Does this sound like the rambling manifesto of a defeatist? The point is this: hatred of an object cannot be and end in itself. Remember that self-control is one bite of the fruit of the Spirit. In addition to hatred of sin and self-control, there must be a compelling love for a different object. For the Christian, this focus is the persons of God Himself. Practically, this means that the victory over the fight against sin is at root due to the gift of loving God.
The only fight against sin we can win is won by desiring God. God knows this and has wired us in this way, and perhaps this is why we are continually, repeatedly, and frequently reminded to delight ourselves with and enjoy God in His word. At times, God’s commandment to enjoy Him seems as if it is an old record so scratched that it skips repeatedly. Over and over again. But the call to fight sin by enjoying God is not at odds at the call to fight sin by resisting sin. We do not need to be drunken peasants, as Martin Luther would insult us, falling off the saddle of the horse on one side. Enjoying God does not come to us at the cost of ignoring the Bible’s commands to resist sin. Certainly we should resist sin: Jesus resisted sin to the point of bloodshed and we should seek to imitate him in resistance (Hebrews 12:4). But Jesus also endured the cross for the joy set before him and we should seek to imitate him in joy (Hebrews 12:2). These two examples are but verses apart in the Bible, and they ought to be but little apart in our heart. For Jesus, the chief end of resisting sin was not to resist sin. For Jesus, the chief end of resisting sin is to glorify God by enjoying him forever.
When resisting sin is the end in and of itself, sin becomes the primary object of our attention. But when desiring God is the end of resisting sin, God is the primary object of our affections. One glorifies the resistance of sin; the other glorifies God. One can produce self-confidence; the other produces gospel-confidence. When we fail to resist our sin to the point of bloodshed, may we be reminded and refreshed that our substitute succeeded in this on our behalf. When we fail to resist our sin by enduring our cross for the joy set before us, may we be reminded and refreshed that our substitute succeeded in this on our behalf.
Psychology may be dominantly used as a spear in popular culture, but I believe the gospel can beat it into a pruning hook. Let the theory of ego depletion be a reminder that your chief end is not to simply be a defensive football player pitted against the opponent of sin. Let the theory of ego depletion be a reminder that your chief end is to glorify God by enjoying Him. Perhaps that will shape who and where we look towards when we fight our sin: we will find ourselves and our people looking less at our balled fists and more at the beauty of God in the gospel.