These days we tend to think of "roads" as smooth swaths of pavement and judge them by how fast we can drive cars on them. A "path" is something different, suitable only for walking or maybe bicycles, and a "way" has more to do with giving directions than any physical reality. When we get "lost" it usually means we're in a car on an unfamiliar road -- a far cry from being in the middle of a trackless wilderness with no idea which direction to go. The ancient world was very different, with isolated towns and endless square miles of trackless wilderness. Then a "way" was a set of landmarks to follow to get from one place to another through the wilderness. A "path" was a way used enough to leave a visible trace on the ground, and a "road" was a heavily used path, easily followed and walkable. So it makes sense that when used in the Bible, all three terms represent guiding truth, ideas that lead us where we want to go. This is pictured in the modern use of "way" -- when we talk about the "way" to do something or the "way" to get somewhere. We're talking about the correct, best, most efficient method of doing something or getting somewhere. And it's good information -- truth -- that helps us find that best way.

In most cases, "mouth" in the Bible represents thought and logic, especially the kind of active, concrete thought that is connected with speech. The reason for this is pretty obvious, but it also holds when people, for instance, remove a stone from the mouth of a well, which represents gaining access to spiritual ideas. The mouth is used for eating as well as speaking, of course. In those circumstances, it represents our first, most external perception of a new spiritual idea or desire. This also makes sense, mirroring the way tasting food in the mouth gives us an instant impression of the quality of the food.