Eigth grade graduation theme song suggestions?

I am in eigth grade currently and we get to pick our theme song for the graduation ceremony when they are showing the pictures of us and stuff. (i know its really early but theyre werid at my school like that) It has to be christian (im at a lutheran school) and it should be something kind of mellow-ish i guess. please if you can suggest anything leave a youtube link or some type of site where i can listen to it. THANK YOU IN ADVANCE!!!!