Turn, Turn, Turn (To Everything There Is A Season) - The Byrds
Where Is The Love? - The Blackeyed Peas feat. Justin Timberlake
Changes (That's Just The Way It Is) - Tupac or Bruce Hornsby version
Amerika - Trick Daddy (find an edited version, lol)
Why? (and the remix) - Jadakiss
Keep Your Kead To The Sky - Jadakiss or The Sounds of Blackness version
War (What Is It Good For) - Edwin Starr
One Love - Bob Marley
Love Is Blind - Eve
That's all I can think of right now. Some of em might be a stretch, but there's a message in all of them.

Whut'chu doin in mah head maaiiun??!!!

.. when I saw the OP all the songs I highlighted from your list were on my list... hmmmmmmmmmmmmmmmmmmmmm

The first time I heard the Tupac / Horsnby arrangement it blew my mind because I had never heard it when it first came out but I have the Hornsby album and always like the song.. (yeah I said album..) and where is the love is like .. so in your face from the top down...
*Harvest For The World - Isley Brothers
As - Stevie Wonder
Gotta Be - Desiree
Head To The Sky - EW&F
Spirit - EW&F
Save the Children - EWF
The Bottle - GSH
Under The Hammer - GSH
If I Had A Hammer - Peter Paul & Mary
*People Get Ready - Curtis Mayfield
*Earth Crisis - Steel Pulse
*Shame on the World - The Main Ingrediant
The ones with * are particularly inspirational songs for "secular" music ...
