The world you inhabit is first and foremost a collection of representations. The phenomena which both inhabit and constitute the space in which you consciously live, think, and act are physiologically derived symbols of the objects we assume populate the cosmos. Your biology provides both the grounds and the limitations of these phenomena, and it is fair to say that with a different physiology you very well could experience the world as a vastly different place.
Consider for a moment that the phenomena you encounter - that green, swaying, woody tree over there; the fluttering colors of the flag; the electric touch of another human being - are all derived primarily from the action of five senses. Each of these senses is anatomical in origin: you see because you possess eyes of a certain structure which reacts to photons, you smell because of the interaction of particles with your olfactory nerves, so forth and so on. Your brain is able to process the information from these senses and edit them into something coherent and unified. But these structures only serve to gather specific types of information; they do not give you the full picture. Even though it is quite easy without reflection to assume that this world of phenomena is identical with the reality outside yourself, you need only consider the very different phenomenal worlds which animals with different anatomies possess. Bees, for example, are capable of sensing ultraviolet wavelengths which are absent in your phenomenal world: the representations which they experience differ in terms of the information to which they have access. If you suddenly sprouted an organ that could detect X-rays, your world would appear radically different. The same reality which you naturally assume lies beyond yourself would give rise to a different set of representations given.
There is nothing wrong with this circumstance, of course - you are the product of evolution, a process which is in one sense quite blind of the possibilities open to it: you have developed these particular senses, and thus this particular set of representations, because of a long series of incremental developments each of which had to justify itself in terms of survival, no necessarily in terms of increased information. Another way of saying this is that you have senses which have developed to take advantage of information (but not necessarily all of the information) most relevant to your survival and reproduction. But evolution is not an optimizing process - that is, evolution will not always come up with an optimal structure. Your eye, for example, has the curious property of having a blind spot, because your optical nerve starts from the inside and most make its way out. This is clearly not an optimal design, and it can be contrasted with cephalapods who have developed an eye where the optical nerve is positioned in such a way that it does not have a blind spot. So, too, your anatomy as a whole gives you access to some information and not other information, so that, from the very start, every phenomena you encounter is already a highly specific representation of the reality beyond. In a word, your world has already been interpreted for you from the instant you perceive it.
With this in mind, it is clearly a mistake to idolize your perceptions - that is, to assume that your perceptions are actually the objects in reality rather than merely the representations of those objects. The scientific revolution has likely served to enhance your awareness that the objects in reality have a mind-independent existence, have intrinsic properties which are discoverable through observation, and so forth; but it is also possible that it has made you somewhat forgetful that all of your observations are already interpreted and biased by your anatomy. Scientists themselves are generally keenly aware of this fact and are especially aware of the limitations of our sensory inputs, and must use devices that transform the information that is not available to us through their anatomy into information that they can sense: they make devices that sense X-rays, for example, and then represent those X-rays in terms of visible light. Of course, in these circumstances there have already been two acts of interpretation the moment the scientist experiences the phenomena: one, the mechanical interpretation or representation, and secondly the representation of that representation by means of human physiology.
Nevertheless, this situation is only the most basic foundation or grounds for the world of phenomena you experience; it does not, in itself, constitute a full world. The representations which fill your world are not merely neutral or indifferent representations of sensory information: they are interpreted according to the social constructs in which you were raised and which you have appropriated through a variable blend of acceptance and rejection. You analyze and evaluate the representations by means of a dazzlingly complex set of social symbols - the most obvious of which is language. By means of language, you categorize the phenomena by names, and through the symbolism of names you are able to give meaning to the representations, understand their relationships, and even learn how to manipulate the reality they represent. You experience this process as a process of discovery - that is, when you are educated and socialized, you experience your particular society's social symbols and structures as a given indistinguishable from non-social reality. Here is a boulder: you cannot move it, it was there before you were born, it is part of reality. So too you experience grammar as something beyond your control, something out there, something fundamentally part of reality. You will discover, of course, if you are clever, that the two are not quite the same: your language is a product of society and culture. It does have reality, for sure: you cannot simply use whatever words or syntax you wish and expect to be understood. But its reality is the product of a very specific series of events within human society, and the language exists only so long as it is used - that is, it is dependent on human action for its reality. As such, it is also shaped by its use: they symbols you use to represent reality are themselves subject to flux.
This is not to say that you are "trapped" in a negative way within your culture - that would be like complaining that you are trapped in your body. Your body is the means by which you experience reality - its limitations are the flip-side of its abilities. So too the social symbols you use are the means by which you know reality. Your beliefs about reality - all of which are made in terms of these changing symbols - are not "false" simply because they are composed of symbols whose relevance and validity are historically and socially contingent any more than your visual experience of a tree is "false" simply because it is contingent on your specific physiology. Your visual representation of a tree is a representation, sure: but it is a representation of something, some object, and even if it is flawed in some way (as it is even when you are at your most healthy) it still is reporting information about reality, information that can be used to check and either confirm, refine, or discard the social symbols. It is true that there is no known way to escape the representations - that is, to experience reality in a way unfiltered by these physiological and social structures (not even, contrary to some who have read Huxley's Doors of Perceptions, mind-altering drugs: this only serves to distort and alter the representations into something unfamiliar that might be taken to be the "underlying truth of things," but which is really no more enlightening that viewing yourself in a fun-house mirror). But because the representations are based in reality, there is the possibility of correction - that is, the possibility that through the careful manipulation, comparison, study, and reflection upon your social and phenomenological symbols, you can refine those social symbols in a way that better represents the reality.
This has been the human quest. At its best, it is like a function approaching an asymptote: you get closer and closer to reality with each refinement, but the symbol will never be identical to reality. Practically speaking, things are far more bumpy - and this is not even taking into account the fact that reality is itself in flux along with society and yourself. But it is a good reason to be both optimistic that truth - understood as the conformity of your symbols with reality - is possible, even if the absolute remains out of reach. It is also a reason to be skeptical and reflective of the claim that a particular set of symbols is perfect: that is, that it identical with reality. This is dogmatism, and it is a form of conceptual idolatry that fails to recognize that the symbols it uses are contextualized both by human physiology and society - and that, for that reason, all systems of symbols necessarily fall short of describing reality perfectly. This imperfection suggests strongly that you should be a fallibilist: that is, you should view all your representations as potentially flawed in some way. "Flawed" does not necessarily mean "false." Geocentrism is clearly flawed, but it is not altogether "false," because it does model the phenomena of reality: the sun rising each morning, the procession and recession of planets, and so forth. There is much in it that is, indeed, true, and it is arguable that without that series of representations modern science might not have ever come about. But the fallibilist is willing to modify or even set aside such venerable symbols because he recognizes that they are, in the end, constructs: mental tools, whose usefulness may very well be contingent on a very specific set of circumstances.
I have only described phenomena, symbols, and representations in a very superficial way, and I must accept my own conclusion that my account is quite possibly flawed, but I hope that you will accept that there is much about it that is true. The implications for religion are most interesting to me right now, and I leave most of them for a later note. But I would like to simply say that these insights do not make religion invalid. Atheism can be as dogmatic as religion, and there is just as much conceptual idolization and self-deceit going on in the atheist who shouts that a wafer cannot become the body of Christ as there is in the soothsayer who interprets the movements of birds to be a sign of fate. In all these matters, the key insight is not a matter so much of truth or falsity, but a matter of context and absolutes, because even what counts as true and false is dependent upon the structure of our social symbols. The Incarnation in Christianity presents this for my closing meditation: let us say that God becomes a man and wishes to reveal something of Himself to us. He must use our symbols to communicate to our minds, and thus whatever He reveals will take on the limitations of the symbols He says it in. Even if somehow He were able to undo the limitations of human physiology and culture - if through some miraculous process He destroyed all the structures that we use for thought as we know it and replaced it with an unmediated experience of His reality - the moment we attempted to communicate it or act on it within a social, human context, we would be again forced to use symbols, and once again would be in the position of the human: the thinking, growing, changing, limited, mortal thing called man.