A review of the Lanterns season finale, "Dirt and Stars" — with spoilers — coming up just as soon as just as soon as I write "leave town, asshole" on your lawn with my own manure...
"In brightest day, in darkest night, I embrace my fear, I'll do what's right. I choose this ring, I choose this fight... in service to this lantern's light."
This is the oath that John Stewart improvises as he charges his ring for the first time as an "independent contractor" Green Lantern. It's structurally similar to, but thematically quite different from, the classic oath from the comics, which we heard Hal rush through in an earlier episode:
“In brightest day, in blackest night, no evil shall escape my sight. Let those who worship evil's might beware my power...Green Lantern's light!"
The official oath sounds like the words of someone absolutely sure of their righteous position at all times. The latter takes the judgment out of it, pairs the idea of embracing fear with doing right — as if to say that only a person who understands fear can be trusted to know what's right — and presents the job of Green Lantern as something John has decided on for himself, rather than something his parents pushed him towards for his entire life.