Neithan Tol Turambar

I believe that the ring symbolizes materialism in the sense of power. The power of the Valar was a material power derived from Eru himself, direct power to alter even the material form of Arda, (Middle Earth), because although, as when this power was used by the Valar during the shaping of the world, the Valar acted spontaneously and independently of Eru, still while they were moving with power to fashion the shape and design of the world, they knew that everything that they did was already complete and entirely within the will and mind of Eru, 'The One'.
Sauron was of the Maiar, like second-class angels of lesser power, if you will, and the power of the maiar was not that of the Valar, who were like first class angels, who could command the very stone of the earth to rend, or the sea to rise and drown whole lands, but the power of the Maiar was not with the stone, or the lightning, or the water, or fire, elemental, so to speak, but was with the idea, the word, the feeling, the meaning, the truth, the image.
Before the ring was made Saurons power as a Maiar was like that power you feel in the presence of old man who is wealthy and powerful, and who has commanded respect by demonstrating superior ability his entire life. That vague feeling of mingled respect, envy, and fear when you are in the presence of someone like that, where you find that you have humbled yourself without willing to do so. That was the power he had. He could use that power and his words to inspire men, to move them to fear or doubt, to influence the path of their thoughts to conclusions that he himself had planned for them, and yet they would foolishly believe that they had arrived at a decision based on their own insight. He could daunt and inspire fear in the hearts of lesser men, or sow doubt and suspiscion in the minds of the wise. But he could not force. He could not by sheer power alone completely overide the will of any save his most miserable servants, orcs and trolls and such. For example: If he were to destroy an army and king garrisoned behind stone wall and iron gate; he could by clever parley and crooked counsel, if heeded by the gate messenger and the king, convince the king to open the gate and thus save his people from eventual starvation, but he could not by command cause the material elements that made the castle door to rend asunder, or at least his power over the things of the Earth was limited.
By the forging of the ring, by some secret art of long study he developed a way of taking a large part of his inherent power and by placing it in the form of a ring, to change his power into a far more direct and present and tangible form. I am probabily wrong at many points but I think I have it in a general way.
Sauron also taught this secret to the Elves, because if he could get them to place their power in material form by direction of his arts, that act of doing so, by the Elves, would place them in subjection to his power. Their power would become in a sense materially linked to his, and subject to it because it was from him that their power had evolved into that form. Sauron underestimated the power of the Elves. In the hour of the completion of his design, the Elf Lord Celebrimbor perceived his intent, and 'the three were hidden from him'.
The Elves were far stronger and more numerous at the great battle at the end of the second age, the power of the Numenorean kindoms in exile was still very strong, though in decline. And at that time the very lives, hearts and minds of the Elves and their Lords were directly threatened. If at any time Sauron succeeded in capturing a traveling Elf, or some Lord's messenger, and by torture learn the wherabouts and idenity of a keeper of one of the Three Rings, that knowledge would greatly strengthen him and weaken the possessor of the ring. He did not know which of the Great had the rings. At any time he could by ill chance or design find out. And so the whole combined and entire might of the Elven kingdoms moved as one in great stroke against him, and with the help of the still numerous and strong Gondor, but little removed from the height of it's power and fresh in the living memory of the splendor of Numenor. And there are other powers at work in Middle Earth, powers of good and they are not always distant or idle.
After the end of the second age Sauron's power began to grow again because the Ring was not destroyed. Although it was not in his posession, the greater part of his native power was become material, bound to the ring, so long as the ring continued, so did he. During this time the Elves, on the other hand, faded. The passage to the Grey Havens long hindered, was open, and after many thousands of years and battles, many elves began to take to the west. After I believe somewhere in the neighbor hood of 1500 years when the Elves learned for certain, that the ring was not destroyed, and Sauron had risen again, They could not muster again the resolve to suffer the carnage of another great war for middle earth. They could leave. They would leave.
Yes the Elves and Numenorean exiles won the war, but at exceptional cost. Close to half the number of all the Elves and Men of the West who could wield blade died in that war. Men were bound to Middle Earth, the Elves were not. And even if the Elves once again united against Sauron, and the Ring were destroyed, then the Power of the Elven rings would also cease. Such was the evil of Sauron. So either way, the Elven lords would also lose their power. But better to leave middle Earth, that to become the slaves of Sauron or to dwindle into a secret and wild people of the wilderness and finally fade out altogether. So by the time of the great battle of the Third Age, as was made clear at the Counsel of Elrond, The battle against Sauron and the responsibilty for resistence and the custodianship of Middle-Earth fell to Men, and so great was the burden that Aragorn bore. only Gandalf and Elrond knew fully what that hour meant to him.