It is a bit easier to define what Tolkien would see as "bad" or evil. For Tolkien, "bad" is power used for individual and self- serving gain. Sauron is the embodiment of that which is "bad." He pours out his malice, cruelty, and vengeance in the ring. The owners of the ring have the chance to put right that which is wrong. It is here in which Tolkien would define "bad." The individuals who hold the ring such as Gollum or Isildur are the ones who have the chance to make right that which is wrong in their ability to destroy the ring. Yet, they covet the ring and allow it to corrupt them. For Tolkien, "bad" is being corrupted by power, allowing it to infect the individual who has the chance for good. It is in this where redemption or "good" is action taken in the name of the social maintenance.
Tolkien defines "goodness" as the ability to preserve the social fabric, at times sacrificing oneself for something that enables the betterment of all. Sam would be a good example of this as he is selfless in his devotion to Frodo. Frodo embracing his quest to destroy the ring would embody good, however his being corrupted in the final minutes would be where his goodness is threatened. Tolkien is deliberate in being able to equate good to a notion of self- sacrifice in the name of maintaining the maintenance of the social order. That which is bad is what ignores this larger configuration or seeks to destroy it for individual gain.