Paladins and Paladin Oaths

When someone thinks of Paladins or Paladin Oaths they often times think of The Paladin Order, of knights in shining armor who represent The Mantle's will in the world.
This is half true. Most Paladins are in fact divinely driven and religious, and they do usually use radiant energies to power their magical abilities. But that's not what really defines a Paladin. A "true" Paladin is simply one who has taken a Paladin Oath, an Oath that can be made to a multitude of things.
A Paladin Oath is a magically binding oath that the Paladin willingly enters into. The Oath itself is a set of agreements and ideals the Paladin agrees to uphold, and makes the Oath usually with the help of a Cleric or Wizard which helps bind them to their Oath. This allows them to draw on radiant and magical energies of the world on top of whatever martial abilities they may possess. But woe betide any Paladin who breaks this Oath, just as the Oath gives the Paladin their abilities it can also be broken and take away (or worse) the Paladin's abilities...
The vision of the divinely driven Paladin who serves The Mantle comes from the fact that most Paladins take the Oath of Devotion towards one or all of the Avatars and gods. But there are many other types of Oaths, with some popular ones being an Oath to the Crown, which dedicates a Paladin to a Nation or Monarch, the Oath of Vengeance, sworn by those wronged in some major way, or the Oath of the Ancients, sworn often by members of The Order of Wind and Wood.