When God reveals himself to Moses in the burning bush, he introduces himself by his relationships with Moses' family: "I am the God of your father, the God of Abraham, the God of Isaac and the God of Jacob" (Exod. 3:6). Soon after, God tells Moses to tell the Israelites that his name is "I Am Who I Am," and that "The LORD, the God of your fathers, the God of Abraham, the God of Isaac and the God of Jacob has sent me to you" (3:15). He is not an unknown God -- nor even "El Shaddai," God Almighty, as Abraham, Isaac and Jacob knew him. This is the God who has acted in the lives of your relatives, the God whose hand shaped your family tree. True for Moses, the Israelites, you and me.
I find it hard to wrap my brain around the idea of God as Almighty, or Sovereign, or other of his true-yet-abstract characteristics. Don't just tell me to trust God because he is trustworthy or good. No -- tell me what he has done in your life, or remind me of what the God of Abraham did a few millenia ago, the God of David, the God of Paul. Concrete facts, evidence, help me to realize who God really is. I am God's child and have a direct relationship with him, but it's not unmediated through other people. I need to read God's Word (written by people), to worship and pray with people, to be encouraged by other people also walking with Jesus.
Most of all, of course, the Person I need to mediate my relationship with God is Jesus. As God's Son, he is the ultimate example of the Relational Principle. As "God in man made manifest," he is also the ultimate example of the Incarnational Principle. Relationship and incarnation are intertwined. Through Christ, God has made us his children, an intimate relationship. Through Christ, God gives us his power to work for his glory, but as unique human beings we express his power in unique ways. When we serve God, we do it not as automatons or slaves blindly following our Master's will, but instead as partners with God, as in a Father-son business.
I was recently reading (in the March Touchstone magazine) an editorial contrasting the Koran, which Islam teaches was dictated directly to Muhammed (i.e. no human involvement whatsoever) with the Bible, which was inspired by God yet filtered through human minds and hearts. So the revelation given to us by Isaiah is different than that we have from John, and so on. The diversity, yet consistency, of revelation is breathtaking. Our humanity enhances revelation -- as if that were possible! -- because it reveals God's creative ability to work through any vessel, no matter how broken. Imagine a composer who can create glorious works not only for symphonies but even for the kazoo or pots and pans. That's our God.
To me, this responds to a comment that I periodically hear: "God doesn't need me to do his work. He can accomplish anything he wants." To be fair, let me note that this is said with an emphasis on God's sovereignty and our ineptness, and I agree that this statement is probably true. But I don't see anything in the Bible that supports it, and much that tells me that what we do is extremely important to God. Apparently God rarely chooses to act without human involvement. In fact, God chooses to associate with some really flawed folks. (David, the man after God's own heart? Remember what he did? And Abraham, Isaac and Jacob's families could provide plenty of fodder for a daytime talk show.) For whatever reason, the Incarnational Principle is the way he does business.
Nor can I depend on God giving someone else a task that I decide not to do. Not only does God have other tasks for them, but if God wants me to do something, then he wants it done with the gifts, weaknesses, personality that I bring to it. I can trust that he matches person with mission for a reason, namely his glory. God gave Solomon, not Ezekiel, the commission to write Proverbs. What would have happened if Solomon hadn't done it?
Thinking about this has made me realize that I don't really take seriously enough the holy responsibility of living my life for Jesus, wherever that takes me. It's easier to downplay the importance of my bearing witness to Jesus through my life than to accept that my everyday life has eternal consequences. And surely that is exactly as Satan would have it: "they have conquered him [that is, Satan] by the blood of the Lamb and by the word of their testimony, for they loved not their lives even unto death" (Rev. 12:11). It is awesome, to me, that testifying to God's work in and through us is given a place in this sentence alongside the shed blood of Jesus as defeating Satan. The God who humbled himself by taking on the form of man -- the God who humbled himself by being known by his relationships with highly imperfect people -- is the God who humbles himself by doing his magnificent work through average sinners like you and me.