Damn, I'm stumped. Nirvana isn't right because it's about the state rather than the act of achievement; same for enlightened. Epiphany is also wrong. Salvation for the same reason: it's something you have. Enlighten is something you do to others, not yourself; edify ditto.
GAH!
Come on Saskwach, you're better than this.
Well unless any of those turn out right I'm just dying to give mine anyway (sorry Anarchemitis):
a soft murmuring or rustling sound; whisper.
Starts with s.
Edit: Is it 'divine' by any chance? Also, I don't think your word is, by the way you've described it, an adjective. It might also happen to be one but not in your case; that's a verb.