terrified - literally, said of horses or other animals startled or suddenly scared; so of sudden consternation in general.
which - your not being terrified.
evident token of perdition - if they would only perceive it (2Th 1:5). It attests this, that in contending hopelessly against you, they are only rushing on to their own perdition, not shaking your united faith and constancy.
to you of salvation - The oldest manuscripts read, “of your salvation”; not merely your temporal safety.