“Patience is a weapon. And in the hands of the right person, this weapon is not only deadly, but can also determine victory.”
Related quotes

“The only weapon that we have in our hands this evening is the weapon of protest. That's all.”
Montgomery Bus Boycott speech, at Holt Street Baptist Church (5 December 1955) http://www.blackpast.org/?q=1955-martin-luther-king-jr-montgomery-bus-boycott
1950s
Source: A Testament of Hope: The Essential Writings and Speeches
Context: We are here, we are here this evening because we're tired now. And I want to say that we are not here advocating violence. We have never done that. I want it to be known throughout Montgomery and throughout this nation that we are Christian people. We believe in the Christian religion. We believe in the teachings of Jesus. The only weapon that we have in our hands this evening is the weapon of protest. That's all.

Statement by the United Nations (UN) Independent Expert about how countries must regulate arms trade to prevent human rights violations – http://www.un.org/apps/news/story.asp?NewsID=42578&Cr=Arms+Trade&Cr1#.UeWCAI2nq24.
2012

““Truth is a deadly weapon,” Lady said.
“Which is why priests and princes dread it,” I said.”
Source: Shadow Games (1989), Chapter 25, “Taglios: Scouting Southward” (p. 127)

“A strong personality can maintain itself without the help of this particular weapon.”
Source: The Moral Judgment of the Child (1932), Ch. 1 : The Rules of the Game, § 8 : Conclusions : Motor Rules and the Two Kinds of Respect
Context: Every observer has noted that the younger the child, the less sense he has of his own ego. From the intellectual point of view, he does not distinguish between external and internal, subjective and objective. From the point of view of action, he yields to every suggestion, and if he does oppose to other people's wills — a certain negativism which has been called "the spirit of contradiction" — this only points to his real defenselessness against his surroundings. A strong personality can maintain itself without the help of this particular weapon. The adult and the older child have complete power over him. They impose their opinions and their wishes, and the child accepts them without knowing that he does so. Only — and this is the other side of the picture — as the child does not dissociate his ego from the environment, whether physical or social, he mixes into all his thoughts and all his actions, ideas and practices that are due to the intervention of his ego and which, just because he fails to recognize them as subjective, exercise a check upon his complete socialization. From the intellectual point of view, he mingles his own fantasies with accepted opinions, whence arise pseudo lies (or sincere lies), syncretism, and all the features of child thought. From the point of view of action, he interprets in his own fashion the examples he has adopted, whence the egocentric form of play we were examining above. The only way of avoiding these individual refractions would lie in true cooperation, such that both child and senior would each make allowance for his own individuality and for the realities that were held in common.
“Art is a weapon and the weapons can change the world.”
"Art" at riikosakkinen.com http://www.riikosakkinen.com/info/quotes/
Context: Art is a weapon and the weapons can change the world.
Good art is irreverent, excessive, controversial, incorrect, irritating, ironic, bad behaving, playful and beautiful or ugly.