I don't think so. "In the blink of an eye" is a regular expression, so can be used in many a context. When looking at the lyrics of New Moon (losing my soul in a blink of an eye") and Under Fire ("in the blink of an eye I took someones life"), I don't see a resemblance.
New Moon (lyrics by Ted) is (at least that's how I read it) about someone getting another chance. Could be a religious song, a "see the light" lyric. Ted, please enlighten us (no pun intended...).
Under Fire (lyrics by Doug and Ted) is about the things you can ask yourself after killing someone during a war. Government tells you to kill the enemy, but the enemy is also a human being, a father, a loving son.
So to me there is no connection between those songs except the choices in life you can make or have to make.
If that's a theme, then Enchant and many others are writing concept albums all the time. I don't see it as a theme, but an inspiration - writing lyrics about the things you think about, things that worry you or make you happy, ie. real life things.
Some people write about fairies and hobbits, some about nothing at all and think of a reason afterwards, some write about real life stuff.
Another very good example (IMHO) of a band writing about real life is German band Everon, who I am going to see tonight, actually.
Nice topic!
Jerry