Psalm 43:3-4 (ESV) reads: "Send out your light and your truth; let them lead me; let them bring me to your holy hill and to your dwelling! Then I will go to the altar of God, to God my exceeding joy, and I will praise you with the lyre, O God, my God."
My first thought as I read this was that the emboldened words and phrase all remind me of the language that surrounds Jesus, both from him and the narrator, in John's Gospel. Jesus is the "true light" (Jn. 1:9), "full of grace and truth" (1:14), the "light of the world" (8:12), and the "way, the truth, and the life" (14:6). Further, he is the Word-became-flesh who "dwelt among us" (1:14, where the Greek for "dwelt" is the OT word that describes the tabernacle, where God's presence was centrally located in Israel) and the major thrust of Jn. 2:13-22 (the cleansing of the temple passage) is that Jesus is the temple.
In short, John presents Jesus as the truth and the light that leads us to God's presence, whcih is found in Him.
Considering how steeped the Fourth Gospel is in the Old Testament, it is reasonable to think that John and Jesus may well have had Ps. 43:3-4 in mind when they used all of that language.
But this is more than just fun Biblical intertextuality (though it certainly is that). It appears that in Ps. 43:3-4, light and truth are figurative. The Psalmist pleads with God to send His spiritual light and truth to lead back to His presence.
When this language is applied to Jesus though, what for the Psalmist is figurative becomes quite actual. Of course, Jesus was not a beam of light, but He was and is physical. He doesn't just provide light; he somehow is light. He doesn't just speak truth; he somehow is truth. And he doesn't just lead us back to God's presence; he is God's presence. The Psalmist never could have expected just how fully God would answer his prayer!
All of the figurative light, truth, and God's presence language in Ps. 43 is still pretty common today, and not just for Jews and Christians. It sounds quite a bit like the language of all kinds of New Age spirituality, doesn't it?
But for the New Age spiritualist, all that "light" and "truth" and even "presence of God" language is even more figurative than it is for the Psalmist. New Age spirituality in all its forms (think Unitarianism and other mysticisms) is obsessed with the incomprehensible, mysterious aspects of God, such that almost all of the langauge is ultra-figurative, broad, and vague.
And I understand the appeal to that in one sense: no doubt much of evangelical Christianity in America has been all too comfortable with the God of the universe. He does seem rather "figured out" in many of our worship services, doesn't He? But the obsession with mystery never gets you anywhere: how can you have any real relationship with someone you can't really know at all?
It also flies in the face of one of the most precious Christian teachings, namely that Jesus Christ is the ultimate unique revelation of God. What I love about being a Christian is that I get somewhere with God. Knowing Jesus means knowing God. It means knowing Him truly even if never fully (oh and be assured- you never know Him fully). I can once affirm that God is both incomprehensible and knowable.
And I can only affirm that because Jesus came as the true light that leads us to God Himself, sent by God to reveal God to all of us. If God sent us the true revelation of Himself that leads us to Him, why are humans so hesitant to embrace it in favor of dead-end vagueness? He wanted us to know Him, and that is for our good.
New Ageism has never appealed to me for precisely this reason. How often the New Age-ist seems to say much without ever really saying anything! I never want to have God "figured out," but I do want to know Him, and I want to know Him actually. I rejoice that I can do that in Jesus.