This motif goes to the essence of Dr. King's understanding of Christianity. Whether he was talking about Black and white children holding hands, or speaking out against the war in Vietnam, Dr. King cared about the well-being of everyone in the world. Again and again throughout his life he invoked the common brother (and sister) hood of humanity, the commonalities of oppressed peoples' struggles, and the shared fate of the world.

As he writes in the opening of "Letter from Birmingham Jail":

[…] I am cognizant of the interrelatedness of all communities and states. I cannot sit idly by in Atlanta and not be concerned about what happens in Birmingham. Injustice anywhere is a threat to justice everywhere. We are caught in an inescapable network of mutuality, tied in a single garment of destiny. Whatever affects one directly, affects all indirectly. Never again can we afford to live with the narrow, provincial "outside agitator" idea. Anyone who lives inside the United States can never be considered an outsider anywhere within its bounds. (4)

Though it may not seem like it when it's taken out of context, this paragraph was answering the critics who had called him and the SCLC "outsiders" for coming to Birmingham from Atlanta, Georgia. Of course, Dr. King found that to be an extremely weak criticism. But he didn't just politely dispel that petty sectarian notion. He blasted it out of the park.