Excellent thread. Excellent suggestions here. My reason for even coming to this thread is that I run an online radio show that intentionally blends secular music and so-called "Christian" artists (man, I know I am opening myself up with that designation) that are spiritually themed or reflect/consider a world view consistent with Christian faith (another vague comment open to critique...let's just say I'm not playing Motley Crue's "Girls, Girls, Girls." Okay?). I'll make my shameless plug below, but for now I need to stick to the thread...
Here are some more suggestions that I have featured on my show:
Blindside - Actually, these guys are Christians that have larger secular appeal. Cut of the same die as POD.
John Mayer - Check out "Bigger Than My Body" and "Something's Missing." Neither are necessarily spiritual, but good life stuff.
Linkin Park - Mostly whining and angst (aka - popular music), but good discussion starter stuff.
Lifehouse
Audioslave - Chris Cornell communicates a lot of spiritual musings in his lyrics. Certainly not Christian, but good, thoughtful stuff nonetheless.
Okay, at the risk of being accused of spamming, my shameless promotion is below...
My Internet broadcast radio show is called Righteous Rock Radio. It IS NOT a proselyting effort, rather a music program done by Christian dude who just loves music and believes the art of music speaks and has volumes to say (not preach, but say). As I like to try and explain to others, imagine if FM radio wasn't so sappy and tepid, and AM Talk radio had cool music bookmarked by meaningful discussions about what the music might be saying about life, love, politics, culture, etc. That's my show. If you want to check it out and perhaps find some more material you can visit my website at RighteousRockRadio.com.
Peace!
PC