It is the Spirit who gives life; the flesh is no help at all. The words that I have spoken to you are spirit and life. ⁶⁴ But there are some of you who do not believe.” (For Jesus knew from the beginning who those were who did not believe, and who it was who would betray him.)
— John 6:63–64 —

The doctrine of illumination explains how spiritual insight is given to God’s children by the Holy Spirit. The locus classicus for this doctrine is 1 Corinthians 2:10–16, where the Apostle Paul explains the difference between those with the Spirit and those without. Describing this difference, he identifies two kinds of people—the natural man (i.e., the man without the Spirit) and the spiritual man (i.e., the man with the gift of the Spirit). In Paul’s thinking, there is no third category. The only way a man can rightly understand the mind of God is to have God himself reveal himself to the man. This occurs first in conversion, but then progressively in sanctification as the Spirit continues to instruct the saints through God’s Word (cf. John 17:17).

Going further, doctrine of illumination is the personal and subjective complement to the doctrine of inspiration. Whereas the Spirit inspired the words of the biblical authors (2 Pet. 1:19–21), the same Spirit must give light to the Scripture, in order for the child of God to understand God, his world, and his salvation. Without this illumination, the sinner remains in the dark—totally lost and wholly unable to find God (cf. Acts 17:27).

Light and Darkness in John’s Gospel

Importantly, the doctrine of illumination is not only found in the letters of Paul, it is also witnessed in the Gospel of John. Yet, this doctrine is not described propositionally, as in 1 Corinthians 2:10–16. It is revealed thematically, especially in the paired imagery of light and darkness. Indeed, in John 2–4, it is not accidental that Nicodemus comes to Jesus in the night (John 3:2). Night symbolizes his darkness, manifested in his misunderstanding of Jesus (3:1–15). By contrast, the woman at the well comes at noonday (4:6), revealing the light that she will soon receive. 

These are just two examples of the way John presents spiritual darkness and spiritual light. But there are more, and in John 6, we find this theme is a central feature of the debate between Jesus, his disciples, and the crowds. Commenting on this point, R. H. Lightfoot provides a helpful summary of spiritual darkness of Jesus followers.

All through [John 6], except for St. Peter’s confession at 6:68, 69, emphasis is laid on the inability of those addressed by the Lord to rise to what we may describe as a spiritual understanding, an understanding not bounded by material, physical considerations. Thus

at 6:7 Philip deals with the Lord’s question solely at the economic level;

at 6:15, as a result of the Lord’s wonderful gift, there is danger that the multitude will use violence, in order to make Him an ‘earthly’ king, . . .

at 6:19 the disciples are afraid, when the Lord, using means which they cannot understand, approaches their boat in the middle of the lake;

in 6:22–25 St. John is at pains to make clear the inability of the multitude also, relying solely on the evidence of the boats, to understand how the Lord could have reached Capernaum.

At 6:42 the Jews’ difficulty consists in the knowledge, which they think they have, of the Lord’s (solely) natural origin;

and at 6:52 they take His words in the most external sense which the latter can carry, and in that only.

And finally, at 6:60, 61, when many of the Lord’s disciples prove unable to assimilate His teaching about the bread which came down out of heaven, and their participation in it, with the results for them (in other words, about the descent of the Son of man and its purpose), He asks how they are to understand the meaning of the ascent of the Son of man, His return, when His work is completed, to the Father. …

Throughout this chapter therefore, as indeed in this gospel as a whole, the reader is reminded of the Lord’s words in 3:3 to Nicodemus about the necessity of a rebirth from above for vision of, and entry into, the kingdom of God, and thereby for an understanding and reception of the Lord’s Person and His gifts; in a word, for belief on Him. (St John’s Gospel, 154–55, reformatted)

Lightfoot’s list of examples from John 6 illustrate the fact that unless the Lord gives light to darkened minds, knowledge of God will remain a mystery. Even more, Jesus says as much in John 6 when he says that “No one can come to me unless the Father who sent me draws him. And I will raise him up on the last day” (v. 44). And again, in verse 65, he says “This is why I told you that no one can come to me unless it is granted him by the Father.”

Spiritual Illumination is the Work of God

To be certain, coming to Jesus involves more than mental understanding. As Jesus says, it includes eating, drinking, believing, and remaining. But in this full complement of responses, it must also include illumination. Without the work of the Spirit, the flesh can accomplish nothing (John 6:63). And thus, we see what Paul will later detail. Namely, that there are two kinds of people—the natural man and the spiritual man. And the difference between them is not something attainable in the flesh; it is the will of Father, the work of the Son, and the gift of the Spirit that brings God’s children from darkness to light and from death to life.

May we remember that truth and rest in the fact that God delights to reveal himself to his children, even as he delights to hide himself from the proud and self-reliant. Truly, those who search for divine illumination within themselves (a theme of New Age religions) or who seek spiritual light in anyone other than Christ, will remain the dark. But those who have been given light, they will see light. And this is the doctrine and gift of spiritual illumination.

Soli Deo Gloria, ds