“When the Spirit of truth comes, he will guide you into all the truth.” (John 16:13)
As mysterious as this phrase sounds, and as often as these words have led to speculation on what exactly Jesus meant, John Levison (Filled with the Spirit) points out that John’s Gospel gives us an explanation. In the context of John 16, Jesus is talking about his death: its circumstances, its meaning, its results and what will follow. The disciples are in distress, do not yet have the Spirit to help them process and believe, and therefore simply can’t hear what Jesus wants to tell them about his mission (16:12). Grasping the truth will require the Spirit.
Elsewhere in John we get clues from John as to how this process worked. When Jesus says in ch. 2, “Destroy this Temple, and in three days I will raise it up,” everyone assumes he is speaking of Herod’s Temple. But John notes that “he was speaking of the temple of his body. After he was raised from the dead, his disciples remembered that he had said this; and they believed the scripture and the word that Jesus had spoken.” (2:19-22).
And again, when Jesus enters Jerusalem in fulfillment of Zechariah’s words, “His disicples did not understand these things at first, but when Jesus was glorified, they then remembered that these things had been written of him and had been done to him” (12:16).
This is the heart of the Spirit’s mission, then. Not “all truth” as in economics and physiology and the rest, but “all truth,” an understanding of the work that Jesus himself was about to perform. The Holy Spirit “will teach you and remind you of everything that I have said to you” (14:26). As Levison summarizes, “The focus of the paraclete’s vocation is not to predict but to recollect . . . . The holy spirit, in brief, will teach by reminding.” (402)