I found one somewhere on here that I am going to reccommend for this year's Greek Week theme...
"These letters don't make me better than you, these letters make me better than I used to be."
Also, you could adapt:
“
To become truly great, one has to stand with people, not above them.”
You cannot contribute anything to the ideal condition of mind and heart known as Brotherhood, however much you preach, posture, or agree, unless you live it. ~Faith Baldwin
Also try this site compiled by a Phi Mu. http://www.angelfire.com/pa4/phibetamu/greekquotes.html