Fire was not the only picture that God gave the people to help them understand how to approach Him, He also used the picture of a cloud. During the day a cloud engulfed the tabernacle, so that everyone would know that the movable temple was there, but at the same time not be able to see it with complete clarity.
Almost every major tragedy in the faith community has begun with someone feeling that they had finally and completely figured God out. They understood completely who God was and what He wanted, and felt that God had spoken the last word they ever needed to hear. The next thing you know armies were being send to Jerusalem or “witches” were being burned. Nothing is more terrifying that someone saying that they know with certainty all that God is and all He wants for the world. That sort of arrogance leads people to stop listening and stop learning. If God is… well, God, if He set everything we are and understand into motion at creation, then He is much bigger than we can wrap our frail minds around. Even if everything I know about God is 100% accurate (and it isn’t), there are still worlds of things I don’t know about Him, truths and insights I have yet to scratch the surface of. To put it simply, God is much bigger than I am.
It would be a mistake, however, to assume that since we can’t know everything about God that we can’t know anything about Him. The God we find in the Bible seeks to make Himself known to His people, and delights in knowing and being known. Therefore, we must reject arrogance on one side and apathy on the other. The middle ground (where truth is often found, but is also often messy) is that when we look for God we are able to see him. The vision is dim at times as if He is shrouded by clouds and fog, but He is there to be found nonetheless. God's plan seems to be less about learning everything there is to know about Him, and more about learning to love and trust what we do know. Knowledge of God is meant to be relational and not just intellectual. The process of seeking and loving and trusting keeps us humble. It also places us in the center of the strange paradox of hungering to know Him more and at the same time being deeply satisfied in what we do know.