Illumination: The Forgotten Doctrine

by Derek Brown

Have you ever noticed how many times the author of Psalm 119 asks for God to teach him his Word? The request for divine assistance in understanding Scripture is a steady refrain throughout the psalm: “Blessed are you, O LORD; teach me your statutes” (v. 12);  “Open my eyes, that I may behold wondrous things out of your law” (v. 18); “When I told of my ways, you answered me; teach me your statutes!” (v. 26); “Make me understand the way of your precepts, and I will meditate on your wondrous works” (v. 27; see also 33, 34, 64, 66, 68, 73, 125, 130, 169). 

The psalmist knows that he is unable to rightly grasp the meaning of and apply the Scripture without God’s help, so he pleads over and over for God to give him insight into the word of God. The psalmist is praying for illumination.  

The Doctrine of Illumination 
While you may not hear much talk about the doctrine of illumination these days, the truth is that it is a vital biblical teaching. Indeed, we couldn’t be saved without it. Illumination is what God’s Spirit does when he enables our minds to understand the gospel and behold the beauty of Christ (2 Cor 4:6). Saving faith is impossible without divine illumination because we are spiritually incapable of grasping the worth and glory of Jesus Christ in the gospel. The natural hardness of our hearts traps us in spiritual ignorance and darkens our mind (Eph 4:18), making our minds hostile to God (Col 1:13). Meanwhile, Satan is actively blinding us from seeing Christ for who he really is (2 Cor 4:4). We are in desperate need of God’s gracious act of illumination.

But even after we are saved we are still in desperate need of God’s illuminating work. We need God’s Spirit to continually open our eyes to behold wonderful things in his law; we are always in need of God’s Spirit to help us understand his Word. The author of Psalm 119 felt keenly this need for divine illumination. 

What Does it Mean to “Understand”
Just as important as defining illumination positively is explaining what it isn’t. Illumination is not the act of God downloading content into our minds after we’ve prayed, although some pastors may give this impression when they tell stories of the times when they didn’t have time to prepare for the Sunday but God “gave” them a sermon on Saturday night after they asked God for help. Nor is illumination the act of God providing additional revelation to our minds. Rather, illumination is God enabling us to understand the revelation he has already given us in his word.

But understanding the word of God is more than just intellectual comprehension. To “understand” in a biblical sense is to (1) grasp the linguistic meaning of a particular truth or set of truths, (2) embrace the universal reality of that truth or set of truths, and (3) taste the spiritual goodness of that truth or set of truths with the heart (Luke 24:25-32; 44-45; John 6:52-64; 1 Cor 2:11-14). True understanding leads to practical obedience (Psalm 119:34), and practical obedience opens the mind to grow in understanding (Psalm 119:100).

I believe the parable of the soils supports this three-fold definition of “understand.” The first soil was hard and impenetrable, so the heart did not understand what it heard and Satan eventually stole the seed of the word away (Matt 13:19-20). In this case, the heart didn’t grasp the linguistic meaning of the gospel.

The second soil understood enough of the truth to experience some initial joy, but this person didn’t embrace the universal reality of those truths so when persecution came along, unbelief prevailed because this person couldn’t see beyond their temporal troubles into a glorious future inheritance (Matt 13:20-21).

The third soil seemed to start off fine, but eventually the pleasures of life and the deceitfulness of riches choked out the word because this person had not truly tasted the compelling goodness of the gospel (Matt 13:22). This person may have understood the gospel and even recognized the universal character of gospel truths. But he had not tasted the excellency of Christ and was therefore susceptible to competing pleasures.  

The fourth soil, Jesus tells us, fully embraced the gospel and therefore bore the fruit that grows out of genuine salvation. It is no wonder, then, why Jesus contrasts the fourth soil with the other three by saying that this was the one “who hears the word and understands it” (Matt 13:23). To understand in this case means far more than grasping intellectual content: it is seeing the reality of those truths and tasting of their sweetness. 

How Illumination Works
This leads us to our final point. Although illumination is more than God giving us a mental grasp of divine truth, it is never less. In order to experience illumination, it is important that we pursue the means by which God has determined to provide illumination.

First, we must think about the Word of God. God does not bypass the mind in order to affect the will. No, he works through our minds, which is why Paul instructs Timothy to “think over what I say, for the Lord will give you understanding in everything” (1 Tim 2:7). The ability to understand divine truth was a gift from God, but it came by way of Timothy thinking about the truth. If you want to experience illumination, you must think over Scripture. 

Second, we must pray. Psalm 119 is instructive to us because the author models how a believer should respond to God’s Word: with regular requests for God’s help. Prayerlessness is a sign of pride because it indicates that we are depending too much on ourselves and our ability to understand Scripture. 

Finally and related to number two, we must humble ourselves before the Lord. If we would understand Scripture in the three-fold way I described above, we must recognize our desperate situation and recognize that only God can enable us to know his Word. The truth that “God opposes the proud, but gives grace to the humble” (James 4:6) applies to every aspect of our Christian life, including our reading and study of Scripture. David reminds us that, “He leads the humble in what is right, and teaches the humble his way” (Ps 25:9). May we search the Scriptures diligently, pray continually, and humble ourselves before God so that he might teach us his statutes.