“Darkness cannot drive out darkness; only light can do that. Hate cannot drive out hate; only love can do that” (Martin Luther King Jr., 67). In history there are always confrontations between good and evil, light and dark. In a time of segregation and hate, Martin Luther King Jr. must fight the darkness that lives inside the white moderate. Martin Luther King Jr. describes this struggle for justice in Birmingham, Alabama and the rest of America, as the struggle for light to overcome darkness by using powerful imagery in a Letter From Birmingham Jail.
King writes a vivid description of the darkness that exists in not only his situation but the lives of the whole black community. They had hopes and dreams of a time of light but “as in so many past experiences, our hopes had been blasted and the shadow of deep disappointment settled upon us” (8). This shows how through allusion, the author makes his point to the clergymen that blacks had given the white moderate ample opportunity to amend their past transgressions by associating the blacks struggle for liberty with lights’ struggle with dark. Hate, darkness, evil, injustice, all of these are words that King uses to describe the problem that exists in society. His imagery draws a striking picture of a living, breathing evil in every man that does not step forward to end injustice. These ideas that he gives to the reader instill a feeling of guilt and the need to rethink one’s own prejudice towards others.
In contrast to the darkness,  the author refers to the theme of light throughout his letter that can contradict and dissolve the shadows he reveals in the white moderate. ”Injustice must be exposed, [...] to the light of human conscience and the air of national opinion before it can be cured” ( 24). By referring to the human conscience as ‘light’ King infers that injustice is an evil that must be ameliorated. He promotes the idea that all men are created under the light of god, and that in the end light and justice will prevail over darkness and hate. The effect of these words is that it describes an ideal to strive towards, to not only search for a way to illuminate one’s own shadows, but to help others do so as well.
As the author dances between the blackness that resides in the souls of those that would do nothing to create equality and the light of justice and righteousness, he shows how light will eventually overcome. To conclude his letter he states his hope that one day “the dark clouds of racial prejudice will soon pass away [...] and in some not too distant tomorrow the radiant stars of love and brotherhood will shine over our great nation” ( 50). This imagery paints a picture of justice overcoming prejudice and creates a world for the reader in which light prevails.
Altogether Martin Luther King Jr. writes with compelling symbolism of a possible time where peoples’ thoughts are unclouded by racial prejudice.  He describes the predicament that the colored community faces and the path that needs to be taken to fix it, by associating this undertaking with the war between light and dark. His words of a resplendent future, where equity conquers prejudice, touches the reader in a way that they understand, on a deeper level, what the black community is thrown up against and what is required for a brighter future. After reading Martin Luther King Jr.’s letter, the reader finally understands that the black’s predicament is not created by the KKK, or the radicals, but by the people that would rather promote order than justice. “Our lives begin to end the day we become silent about things that matter” (Martin Luther King Jr.). The same people that live their lives side by side with a shadow of injustice that stains their idea of a solution to one not of morality and equality but of invisible walls that continue to segregate whites and blacks.

Sources:

King, Martin Luther. Where Do We Go from Here: Chaos or Community? New York: Harper & Row, 1967. Print.

King, Martin Luther, Jr. ""Letter From a Birmingham Jail"" "Letter From a Birmingham Jail" N.p., n.d. Web. 19 Apr. 2015.

King, Martin Luther, and James Melvin. Washington. I Have a Dream: Writings and Speeches That Changed the World. San Francisco: HarperSanFrancisco, 1992. Print.