Franz Bardon is the only author I know of who simply yet profoundly expounds upon the elements.
While we say that there are four elements, there is actually only two; the masculine (active) and feminine (passive), also known as the electric and magnetic fluids. Their symbol is the Sun and Moon. The element of air, which is active, is the equilibrating element, and earth, which is passive, is the solidification of the interplay between the elements. Each element has a positive and negative pole.
The elements work on the physical, astral and mental planes. On our physical plane, we do not see the pure elements. They are all earth, because everything corporeal is manifested by the mixture of the elements - in physical fire, the element of fire dominates, but it is still a mixture. To a certain degree we can understand the elements by analogy, but taking it litteraly is not very wise. It would be like confusing the soul with the body.
Ether is God Himself, and out of His Infinite Mind does the elements spring.
I see that you are a Christian, so perhaps I can explain it further to my limited capabilities. We read in Genesis:
"In the beginning God created the heaven and the earth." -- heaven is the first element of fire, which is the purest, and earth is the final element of realization, which is the grossest.
"And the earth was without form, and void; and darkness was upon the face of the deep. And the Spirit of God moved upon the face of the waters." -- since earth was without form, it is clear that the elements were not as yet created. Darkness is an aspect of water, but properly speaking, water here is not refering to the element. It is refering to the unmanifested and undifferentiated state of God before creation, both male and female and yet none of them, the primordial chaos, containing all things in potentiality. The creation myth of the Egyptians, Greeks and Hindus contain "the primordial waters" as the first matter as well.
"And God said, Let there be light: and there was light. And God saw the light, that it was good: and God divided the light from the darkness. And God called the light Day, and the darkness he called Night. And the evening and the morning were the first day." -- we see here that fire is the first element, the principle of creation. Light cannot excist without darkness, and therefore fire and water are co-dependent; thus came the differentiated creation to be.
"And God said, Let there be a firmament in the midst of the waters, and let it divide the waters from the waters." -- fire is the creative principle, the firmament which is later called heaven, and water is the created; consider the terms "God the Father" and "Mother Nature." Water has a two-fold symbolism here; one, as the primordial undifferentiation, and two; the differentiated creation.
There are different symbols pertaining to each tradition. The hindu assign the following;
Ether is a black or indigo egg, symbolizing the potentiality of all.
Fire is a red triangle pointing upwards, symbolizing it's source from above, as well as having three angles, the number three being the number of manifestastion, which fire initiates.
Water is a silver crescent moon, symbolizing the inherent duality of the created with its two ends.
Air is a blue circle, symbolizing it's neutral disposition. It is called "wet and dry" because it partakes of both fire and water in its mediumship.
Earth is yellow square, symbolizing the final realization of the four elements.
The Pythagorean system of associating creation with numbers and geomatric figures is also very interresting in this connection. The circle is the perfect shape. It symbolizes the undifferentiated eternity of God. The Monad, that is, number one, is symbolized by a dot in the middle of the circle. This can be seen as the first principle of fire.
The Duad is symbolized by the line, having similar symbolism as the crescent moon.
The Triad is symbolized by a triangle - now, the number three partakes of both one and two, just like air partakes of both fire and water.
The Tetrad is a square. The Pythagoreans considered number four "the greatest miracle."
We can only understand the elements through their emenation and interplay with each other. Franz Bardons Initiation Into Hermetics explains how.