"What is real? How do you define real? If you're talking about what you can feel, what you can smell, what you can taste and see, then real is simply electrical signals interpreted by your brain."
-- Morpheus, "The Matrix"
Morpheus only got it half right. There's really no way for us to know that our perceptions even have anything to do with our brains.
We cannot know anything with absolute certainty. Sure, we can feel absolutely certain about something...but we can never know that our certainty is appropriate. We cannot step outside our context and look at ourselves objectively.
We can look at the world, and we can make careful observations. But we cannot prove finally that even have the ability to perceive, nor that our logic is a reliable tool for understanding what we perceive.
Even if we grant ourselves the assumption that our observations are accurate and our logic is reasonable, we cannot be sure that our perceptions and logic are not colored by our culture, by our previous experiences, and our language. How do you describe something for which there is no word? How do you remember it accurately? How do you come to understand it?
In the end, we must be pitied, for while we cannot avoid the idea that we "know" the world, we can never know if we really know.
In comes relativism. To many people, relativism (in its most extreme form) means that each person defines his own reality and simply ignores any "truth" that he doesn't like. That makes Christians uncomfortable, because we have a God who makes rather direct statements about who he is, who we are, and how we should treat him. Many a Christian has opined, quite reasonably, that relativism must be in direct opposition to God. The book of Judges spoke against something a lot like relativism: "In those days Israel had no king; everyone did as he saw fit."
dictionary.com has two definitions for relativism:
1) "A theory, especially in ethics or aesthetics, that conceptions of truth and moral values are not absolute but are relative to the persons or groups holding them."
2) "The philosophical doctrine that all criteria of judgment are relative to the individuals and situations involved"
The key thing to note is that relativism can include groups.
The folly of relativism as we have come to know it to date is that it assumes that each individual is a separate entity. Thus, understanding must be an individual phenomenon. The monolithic unit is inside a sphere of his own reality. All that he knows is what penetrates that sphere. No person has any right to make any assumptions about what does (or should) happen inside that sphere.
But man is not an isolated entity. Every one of our identities is wrapped up in the relationships that we have. Relationships determine what language we speak, and thus what we can easily understand. They determine our cultural assumptions. They determine our preferences, our fears, and our dreams. Man is a communal being.
Thus, man must be modeled as a communal being. Like a colony of children growing up inside a spaceship with no windows, we are unable to see outside our communal box, but within that box we have almost unlimited impact on each other.
But is that any different? Can't a colony of people choose to reject God just as much as any single person?
That depends on whether God is one of the group.
Romans says that "Since the creation of the world God's invisible qualities...have been clearly seen." God has relationship with every person, and has added his bit to the context. We cannot escape it. He interacts with us, in small ways and large, and thus changes us, changes our perceptions of the world, and gives us the vocabulary (or even the non-verbal revelation!) necessary to understand the world in new ways.
We know that we can perceive the world for no better reason than because God tells us that we can. We know that our logic is reasonable for no other reason than God says so. Our knowing is intimately wrapped up with the revelation of God that has been encoded on our unconscious, and on our soul. We understand even the things we cannot express, because encounter with Him creates a relationship and an experience that transcends language.
If all that we know, and all of our confidence in that knowledge, is ultimately anchored in our relationship with God, then we are profoundly relativistic creatures. Our relativism is not the nihilistic, self-centered free relativism of the monolithic "one;" it is instead the worshipful, delighted relativism of the God-centered group.
So, what do we say then? Do we return to the old absolutism because we have relationship with God? No, because God doesn't promise that what he reveals is absolute. It is simply a sufficient approximation. We cannot know, so long as we live within the approximation, the bounds of truth that might be revealed some day. Nor can we know what might have already been revealed to someone else.
For thousands of years, those in relationship with God knew something. It was an absolute truth: "Hear, O Israel: The LORD our God, the LORD is one." They were the first monotheists in history (a remarkable achievement, which allowed them to build Michaelangelo's Chapel in Jerusalem), because they were told by their God that it was so. It became a mantra in their culture - there is only one God.
Imagine their consternation when Christ claimed to be God. "Before Abraham was, I AM!" It was a violation of what they knew to be true. But we (Christians) have, over time, come to the conclusion that the shema was just an approximation. It was true. Yes, the LORD our God is one. But also, there is something else you should know...
So did God lie? Did he shade the truth? No, God simply told them the truth, and it was enough truth for them in that time. Do you really think that our human languages and human brains can understand the realities of God? Everything we know is - or at least might be - just an approximation, an infinite truth compressed into something that a finite, fallen brain can handle.
So how can we tell the difference between "absolute" truths and approximations? The sad fact of the matter is that we can't. Practically by definition, if we can see outside of an approximation to see even the glimmer of possibility that there might be more to know, then approximation is not the limits of our knowledge - God has already revealed something more. Like how the Israelites waited for the Messiah, who they knew was coming but they didn't know what it would be like. When Christ came, he demonstrated (and then later explained) what the Messiah had been all along, and people understood.
So what confidence can we have in what we "know?" Can we really trust God? Should we hedge our bets about anything and everything, just in case God shows us more later? No. We must, as an act of worship, live wholly within the limits of what God has given us today. God has given this to us, as he has said that it is a sufficent approximation for us. To hesitate to live fully in it would be to distrust his provision, which is an act of rebellion exactly like Adam & Eve in the Garden.
We must live today as though what we have been shown so far is "absolute." But we also must live in the humility that God might tell us more at any time. That, too, is something that he has shown us, in our currently sufficient approximation. Or else I couldn't have thought these thoughts, and written this blog.
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About the word "relativism." We live within the context of our larger cultural and Christian community just like we live within the context of God. We cannot, as individuals or as some sub-group, turn our back on the larger community. (A group which defines itself outside of its relationships is no better than an individual who does so.) The word "relativism" has been tarnished in the eyes of our fellow man, and is a stumbling block to our brethren. So let's avoid it. Let's leave the old word behind...even if it, according to the dictionary, might correctly (though only partially) describe us. | 
