So it really depends on what kind of oath you made to who--or you can be an Oath-breaker, where your magic and abilities turn darker. If you take something like Oath of Redemption, that's a Paladin who believes that anyone can turn away from evil, they believe in violence as a last resort, and using it to save lives. An Oath of the Crown Paladin is one who is tied to a civilization or sovereignty, they want to uphold the laws that keep their civilization together.