There are a few additional words, though, I'd like to share, and they come from those whom we can't afford to ignore.
God: "Let there arise from you a group of people inviting what is good, enjoining what is right, and forbidding what is wrong; these are the ones who will be successful." (Quran 3:113)
"O believers, be maintainers of social justice, bearers of witness for God's sake, even though it be against yourselves, or [your] parents or kinsfolk, whether the man be rich or poor, God is over and above them [in preference]. Therefore don't follow your base desires, lest you deviate, and if you swerve or turn aside, then surely God is aware of what you do." (Quran 4: 135)
Prophet Muhammad (S): "A moment of justice is better than seventy years of worship in which you keep fasts and pass the nights in prayers and worship of God."
Ali (husband of Fatima, one of the four perfect women): "To render relief to the distressed and to help the oppressed makes amends for great sins."
Zainab (daughter of Fatima) to the leadership after it killed nearly all the men in the Prophet's (S) family for standing up to corruption and oppression: "Your ideas are unstable! Your government is transitory! While I find speaking to you of no value, I find scolding you to be great!"
Ali Shariati (in his book Hajj: Reflections on Its Rituals): "Now that you are standing in Abraham's position and are going to play his role, live like him, be the architect of the Kabah of your faith. Rescue your people from the lagoon of their life. Re-breathe life into their bodies that are numb and dead from the suffering of oppression and the darkness of ignorance. Encourage them to stand on their feet and give them direction."
Lastly, Imam Khomeini (leader of the 1979 Islamic Revolution of Iran): "This movement rose from the soul of the masses, the soul of the ordinary men and women, and just as the men entered the arena, so too did the esteemed ladies. Indeed, one must say that they played a greater part in this movement than the men; they made more effort. For when the ladies take action, it spurs the men on."