Martin Luther King Jr. said this quote

“ We are going to win our freedom because both the sacred heritage of our nation and the eternal will of the Almighty God are embodied in our echoing demands. So however difficult it is during this period, however difficult it is to continue to live with the agony and the continued existence of racism, however difficult it is to live amidst the constant hurt, the constant insult and the constant disrespect, I can still sing we shall overcome. We shall overcome because the arc of the moral universe is long but it bends towards justice.We shall overcome because Carlisle is right. No lie can live forever. We shall overcome because William Cullen Bryant is right. Truth crushed to earth will rise again. We shall overcome because James Russell Lowell is right. Truth forever on the scaffold, wrong forever on the throne.   Yet that scaffold sways the future. We shall overcome because the Bible is right.  You shall reap what you sow. With this faith we will be able to hew out of the mountain of despair, a stone of hope. With this faith we will be able to transform the jangling discords of our nation into a beautiful symphony of brotherhood. With this faith we will be able to speed up the day when all of God's children all over this nation - black men and white men, Jews and Gentiles, Protestants and Catholics will be able to join hands and sing in the words of the old negro spiritual, Free at Last, Free at Last, Thank God Almighty, We are Free At Last. ”