Martin Luther King, Jr.: Trending quotes (page 15)

Variants (Many of MLKs' speeches were delivered many times with slight variants): An Individual has not started living fully until they can rise above the narrow confines of individualistic concerns to the broader concerns of humanity. Every person must decide at some point, whether they will walk in light of creative altruism or in the darkness of destructive selfishness. This is the judgment: Life's most persistent and urgent question is: 'What are you doing for others?'
As quoted in The Words of Martin Luther King, Jr. by Coretta Scott King, Second Edition (2011), Ch. "Community of Man", p. 3
1950s, Conquering Self-centeredness (1957)

This passage contains some phrases King later used in "Where Do We Go From Here?" (1967) which has a section below.
1950s, Loving Your Enemies (Christmas 1957)
Variant: Returning hate for hate multiplies hate, adding deeper darkness to a night already devoid of stars. Darkness cannot drive out darkness; only light can do that. Hate cannot drive out hate, only love can do that.
Source: Mentioned in "Out of Osama's Death, a Fake Quotation Is Born" by Megan McArdle, The Atlantic (May 2011) http://www.theatlantic.com/national/archive/2011/05/out-of-osamas-death-a-fake-quotation-is-born/238220/, and widely distributed on twitter http://twitter.com/#!/jmadly/status/65314784136011776 as a quote of King, after the death of Osama bin Laden, the first sentence is one written by Jessica Dovey http://i.imgur.com/cqtjw.jpg on her Facebook page, which became improperly combined by others with genuine statements of King, whom she quoted, and which occur in Strength to Love (1963), Ch. 5 : Loving your enemies, and in Where Do We Go from Here : Chaos or Community? (1967), p. 62.
For the full story see "Anatomy of a Fake Quotation" by Megan McArdle, The Atlantic (May 3, 2011) http://www.theatlantic.com/national/archive/2011/05/anatomy-of-a-fake-quotation/238257/ and for the Facebook version of the quote see Did Martin Luther King, Jr. say that “I will not rejoice in the death of one, not even an enemy”? at skeptics.stackexchange.com http://skeptics.stackexchange.com.
Context: Returning hate for hate multiplies hate, adding deeper darkness to a night already devoid of stars. Darkness cannot drive out darkness; only light can do that. Hate cannot drive out hate; only love can do that. Hate multiplies hate, violence multiplies violence, and toughness multiplies toughness in a descending spiral of destruction.
Context: Let us move now from the practical how to the theoretical why: Why should we love our enemies? The first reason is fairly obvious. Returning hate for hate multiplies hate, adding deeper darkness to a night already devoid of stars. Darkness cannot drive out darkness; only light can do that. Hate cannot drive out hate; only love can do that. Hate multiplies hate, violence multiplies violence, and toughness multiplies toughness in a descending spiral of destruction. So when Jesus says "love your enemies," he is setting forth a profound and ultimately inescapable admonition. Have we not come to such an impasse in the modern world that we must love our enemies-or else? The chain reaction of evil-Hate begetting hate, wars producing more wars-must be broken, or we shall be plunged into the dark abyss of annihilation.
Context: I mourn the loss of thousands of precious lives, but I will not rejoice in the death of one, not even an enemy. Returning hate for hate multiplies hate, adding deeper darkness to a night already devoid of stars. Darkness cannot drive out darkness: only light can do that. Hate cannot drive out hate: only love can do that.

1960s, Where Do We Go from Here: Chaos or Community? (1967)
Context: Power properly understood is nothing but the ability to achieve purpose. It is the strength required to bring about social, political and economic change. … Now a lot of us are preachers, and all of us have our moral convictions and concerns, and so often have problems with power. There is nothing wrong with power if power is used correctly. You see, what happened is that some of our philosophers got off base. And one of the great problems of history is that the concepts of love and power have usually been contrasted as opposites — polar opposites — so that love is identified with a resignation of power, and power with a denial of love.
It was this misinterpretation that caused Nietzsche, who was a philosopher of the will to power, to reject the Christian concept of love. It was this same misinterpretation which induced Christian theologians to reject the Nietzschean philosophy of the will to power in the name of the Christian idea of love. Now, we've got to get this thing right. What is needed is a realization that power without love is reckless and abusive, and love without power is sentimental and anemic. Power at its best is love implementing the demands of justice, and justice at its best is power correcting everything that stands against love. And this is what we must see as we move on. What has happened is that we have had it wrong and confused in our own country, and this has led Negro Americans in the past to seek their goals through power devoid of love and conscience.
This is leading a few extremists today to advocate for Negroes the same destructive and conscienceless power that they have justly abhorred in whites. It is precisely this collision of immoral power with powerless morality which constitutes the major crisis of our times.

Source: Why We Can't Wait

1960s, The Quest for Peace and Justice (1964)
Context: There is a sort of poverty of the spirit which stands in glaring contrast to our scientific and technological abundance. The richer we have become materially, the poorer we have become morally and spiritually. We have learned to fly the air like birds and swim the sea like fish, but we have not learned the simple art of living together as brothers.

Source: Why We Can't Wait