Answer:
Martin Luther King Jr. frequently looked up inspiration from Biblical sources, ancient philosophers and theologians.
In his "Letter from a Birmingham Jail", Martin Luther King Jr. resort to Socrates to highlight his practice of a fair form of civil disobedience and non-violence, as a symbol or analogy to back up his interjection outlining the urge of awakening from the "dark depths of prejudice and racism" of society at that time.
In the letter, MLK Jr. outlines that "Socrates felt that it was necessary to create a tension in the mind", so individuals could rise from darkness; and he felt the same kind of tension was necessary at that time so that society could rise from the darkness of prejudice to a place of "understanding and brotherhood".
He didn't say this I just put this here