12 - Who is an infidel?

Who is an infidel? According to dictionary.com it's:

1. An unbeliever with respect to a particular religion, especially Christianity or Islam.
2. One who has no religious beliefs.
3. One who doubts or rejects a particular doctrine, system, or principle.

[Middle English infidele, from Old French, from Latin infidelis, disloyal : in-, not; see in + fidelis, faithful (from fides, faith. See bheidh- in Indo-European Roots).]

If you think about #3 for very long you'll realize that everyone on the planet is an infidel.