One of my many academic and philosophical interests is language. Not in the sense of literature, but in the sense of linguistics, the study of language and it's psychology. We have been speaking, as a species, for far longer than we have been writing or building cities. Language is what enabled the construction of abstract ideas, and it is an integral part of not just human culture, but our physiology.
All children are naturally talented at learning languages. Under a certain age, usually set around 12 by most linguists, you can drop them into a group of anyone and they will learn the language, or even invent a fully featured new one. Language is built into the structure of our brains, and if we are cut off our brains don't develop. Linguistics is a broad field of study now, finally coming into the respect of other sciences since its revolution by Noam Chomsky.
For more on it, the Wiki has good information on linguistics. http://en.wikipedia.org/wiki/Linguistics
This isn't really about linguistics though. While fascinating, it is tangential to my point in this post. A side effect of language being so integral to our thought is a tendency to put more weight on the words themselves. You see this in everyday usage, with 'curse' words making people genuinely upset. Almost every culture has at least an historical trope about powerful words, with things like names having some innate, magical connection to the object or person in question.
From this obsession with words, with labeling, we as a species have developed a unique hole in our reasoning ability. When we label something, we assign the label's properties to it. We believe we can define things, and should they contain similarities to other words, we then assign the related properties to it.
Many of the favorite arguments of the religious involve such word play. A short, and by no means comprehensive list follows:
1. Creation requires a creator - this one is obvious. They label the universe creation, then make the false connection to a related word. Aside from their own arbitrary label, words sharing a root don't logically follow that they must share a relation.
2. God is perfect, and the most perfect being must exist as a quality of perfection. This one is actually a quite high end theological argument, perhaps belying the inherent issues in the entire field of theology. Arbitrarily labeling a hypothetical being as 'perfect' and proceeding to define perfection however you see fit has no effect on reality.
3. God is (insert emotion/vague concept here). Such as the Christian apologetic "God is Love." This is another attempt to define a being into existence. More liberal religious theologians spend a lot of tie denying the human like god of the Bible and try to claim god is some vague emotion or concept. Like the perfection argument, this one is an arbitrary redefinition of a word with the intent of controlling reality.
A recent example: The discovery of the Higgs Boson 'god' particle. Because of its nickname there are many Christian pundits and bloggers and everyday people claiming it proves the existence of god. Because of its nickname.
But this magical words phenomenon is not limited to theologians and under educated theists. I've read works from otherwise brilliant logicians abuse this notion as well. They fail to catch their own circular logic simply because of names. This is, in fact where the notion of defining perfection equals god exists came from. This is the entire basis of the Ontological Argument. It has been refuted time and again by philosophers such as Kant, who point out that existence isn't really a property, but this is just shorthand for the fact that defining something doesn't make it true. Wordplay and hypothetical logic are fun and all, but they don't really affect reality. The universe doesn't much care that you can define it to be the science project of an old, bearded white man in the sky.
Back to non-theistic logicians now. Philosophers of such a logic bent seem to enjoy similar wordplay to the theologians. Starting with any type of premise they often claim they can prove anything. Many of the logic puzzles taught in discrete math classes are really just terrible plays on words. Now this is not to say logic is poorly constructed, merely that many of its biggest fans don't quite grasp the purely hypothetical nature of any given logical construct. Without genuine input, defining your premises however you please is mental masturbation.
For one of the best treatments of logic and truth in a reality based way, see Bertrand Russell's "The Problems of Philosophy" where one of the greatest philosophers of all time explains just how pure philosophical and logical reasoning tend to fail alone.