Communicating the Doctrine of the Trinity Through Analogy

Whenever different theologians have tried in the past to devise various illustrations to better explain the Trinity on human terms, they have often gotten into trouble; some for trying to work the analogous picture too far, and others who simply have used the description in a limited sense but their audience misunderstood them to be saying that "God is only like this...".

So, naturally, I'll have to tread these dangerous waters.  But one caveat before I do, I want to it absolutely clear that I don't think that this illustration is by any means complete, thorough or perfect as a depiction of the mystery of the Triune God or His work in creation.  Note that a portion of this illustration has shamelessly been adapted from an analogy (I assume) that was invented by Kim Riddlebarger to describe the process of progressive revelation.  With that, here goes.

Imagine that you are in a darkened room.  No lights; it's as pitch as the darkest, starless, moonless rural night.  Imagine God as a man who stands outside the room and speaks to you.  You can only hear Him and the only things you know about Him are the things He has spoken to you through the door.  Even the things you know about the darkened room in which you sit are limited to your vain sensual perception and what He has told you about the room.  Imagine that one day, God opens the door just slightly and reaches His arm in and turns on the light in the room.  You are absolutely amazed by what you see.  The elements and character of the room are exactly as God had described them.  You call out to God, and because all you see is the arm, and ask, "God, is that You?".  God replies "yes, it is Me."

Obviously, God turning the light on represents what happened when He came in Christ to proclaim the Kingdom and explained the purposes of the Old Covenant cultic rituals.  But when you ask, "God is that You?" and He answers yes, even though all you saw of Him was a hand, we know that God is more than just a hand, but just as if I was to quietly sneak around a corner of my house into a room occupied by my sons, and if they saw part of my body and cried out, "Dad, is that you?".  even though the portion of my body they saw is only part of me, I can still say, and would say, yes, it is me.  Likewise, Jesus IS God, but He is not all that God is.  God is Father Son and Holy Spirit.