"How wonderful it is that nobody need wait a single moment before starting to improve the world." (Anne Frank)
"If everyone cleaned his own doorsteps, the whole town would be clean." (Mishle Yehoshua)
The 2 quotes above came from Jewish Quote for the Day
"If you believe you can spoil,
Believe you can fix."
(Rav Nachman of Breslav)
"If I am not for myself, who will be for me?
And if I am for myself only, what am I?
And if not now, when?"
(Hillel, Mishneh, Pirke Avot)