One of the more interesting developments in recent philosophy is the so-called "linguistic turn." Much like Kant's Copernican revolution (which recognized that the structures of human subjectivity serve as a filter on reality), the linguistic turn has come to recognize that our consciousness is fundamentally filtered through language. Beginning with the Structuralists and moving to the post-Structuralist, it has come to be observed that there is no inherent relationship between our words about the world and the world itself. We cannot look behind our words and see the world in itself. When we begin to examine our words and their relationship to the world, then we simply use more words and therefore are simply examining them and not the world in itself. For post-Structuralists in particular, this leads to the belief that there is only rhetoric about the world and no real world represented by our language. Reality is in itself a vast grey that is distorted by our reifying use of language. At worst, philosophers have argued that all language is simply a tool of oppression meant to force people into certain categories of being so that they might be controlled and manipulated. To say the least, such a view destroys any ability to talk about real knowledge or truth. It leads to pure nihilism.
Among those who maintain the old Modernist faith (progressive history, scientific realism, atheism or deism, liberal theory of polity, etc.) the primary argument for the realism of language has been evolutionary. If the structures of our cognition function on the basis of language, and if those structures are intended to be evolutionarily adaptable to the environment, wouldn't it make sense that our language would give us true beliefs about the world? This was primarily the argument of Karl Popper and some of the other Analytic philosophers (I believe A. J. Ayres used this one). Nevertheless, as Alvin Plantinga has pointed out, the best evolutionary theory could give us would be the certainty that language and cognition gave us adaptive beliefs, not true ones. For example, random mutation might genetically predispose me to have false beliefs about Lions, but ones that nevertheless kept me away from them. Since these false beliefs kept me away from Lions, I would live on and the genetic material which would dispose me to false yet adaptable beliefs, would also live on through my offspring. For this reason, naturalism cannot actually lead to epistemological realism.
With the projects of 20th century philosophy in ruins beneath our feet, it would be my suggestion that it is only belief in the Triune God of the Bible which can give us a proper account of the unity of word and world. As we have observed, if we center our epistemology on the basis of the human subject and their innate ability to cognitively and linguistically represent reality, then we will always fail. We will always fail because centering knowledge in ourselves, we take upon ourselves the role of being the guarantor of the truthfulness of the structures of reality. Nevertheless, this would mean that we in some odd sense were ourselves were the divine creators of these structures. Only he who creates a thing can in fact guarantee it's truthfulness and trustworthiness. From the perspective of the Biblical narrative, this insistence on our own competency in this regard is in fact a manifestation of our slavery to original sin. We desire to take on God's role and this includes becoming the guarantor of the truthfulness of truth.
Then how should we precede? The Trinitarian account of God's being states that God corresponds to himself and knows himself through his Word. Insofar as his Word contains within itself what God eternally wills for his creatures (he knows what he wills and wills what he knows), he also knows all creatures through his own Word. For this reason, God's eternal Word is the trustworthy basis of all reality. In that he has created creatures in his own image, he has created them in such a way that they know themselves and other creatures through language. Therefore, like the Triune God, humans know themselves and all creatures in a trust-worthy fashion through the word. Therefore, the presupposition of having been created by the Triune God gives a proper and necessary account of how our words are able to mediate truth to us.
This truthfulness can only be guaranteed by an account of being built on the reality of the Triune God. The Unitarian God of Islam and Judaism (or Deism), exists as a supreme and arbitrary will. From his silent and distant throne, he my arbitrarily will as he pleases. For this reason, there is no particular reason to believe that our knowledge is trustworthily represented through our word. God may have arbitrarily willed the unity of the world and our word, or perhaps not. By contrast, in that the Triune God by his very nature corresponds to himself truthfully through his Word (as do all his creatures), there is a necessary truthful unity between our word and the world. In that we made in his image, we must necessarily enjoy the same unity our word and truth that God himself enjoys. For God to set things up otherwise would be contrary to the very structure of his being. It is of course possible that there could be a aporia between word and world could be introduced, but it would be a disruption of God's original good order (i.e. sin and its consequences).