Unless an argument is solely about motivation or emotionality, an emotional appeal is never a legitimate strategy in an argument. Such arguments are fallacious because they focus on emotion rather than providing verifiable or evaluative support.
An appeal to false authority is a subtype of emotional appeal, as is the more obviously fallacious appeal to celebrity. The Bible is fallaciously cited, in the argumentum ad biblium fallacy, as an authority in many an emotional argument emanating from a religious dogmatist.
Irrelevant negative emotions evoked within arguments can include:
Envy (fallacious appeal to envy, argumentum ad invidiam)
Fear (fallacious appeal to fear, scare tactics, appeal to force, argumentum ad metum)
Force (argumentum ad baculum)
Hatred, Spite, Prejudice (fallacious appeal to hatred, stereotypes, against scapegoats, argumentum ad odium)
Pity, Altruism (fallacious appeal to pity, sob story, argumentum ad misericordiam)
Pride or Vanity (fallacious appeal to pride, apple polishing, argumentum ad superbiam)
Irrelevant positive emotions evoked:
Loyalty (fallacious appeal to loyalty, to conformity, bandwagon, peer pressure, argumentum ad populum)
Traditionally, many religious arguments have appealed to fear (eternal damnation) or to positive emotions (love of the Father, salvation, eternal life, heaven, forgiveness). To argue that an army should be mobilized because enemy forces are massed at the border is a much more valid argument than any religious argument founded in supernatural positives or negatives.
“A vast sector of modern advertising... does not appeal to reason but to emotion; like any other kind of hypnoid suggestion, it tries to impress its objects emotionally and then make them submit intellectually.” ~ Eric Fromm
“No form of art goes beyond ordinary consciousness as film does, straight to our emotions, deep into the twilight of the soul.” ~ Ingrid Bergman
"Patriotism is the willingness to kill and be killed for trivial reasons." ~ Bertrand Russell (1872 - 1970)
"Patriotism is often an arbitrary veneration of real estate above principles." ~ George Jean Nathan (1882 - 1958)