From The King Center, in honor of Martin Luther King, Jr.:
“Agape, a Greek word for love, was central to Dr. King’s theology and philosophy of nonviolent social change. He spoke of three kinds of love: philia, affection between friends; eros, romantic love; and agape, a universal, all-embracing love for others for their sake.
In his 1967 “Levels of Love” sermon, he described five levels of love: utilitarian, like the love of master for slave; friendship; romantic love; humanitarian love for humanity in general but not individuals in particular; and agape, unconditional love for every person, regardless of race, religious or political beliefs, whether they are just or unjust, or whether they respect or hate and abuse you.
He defined agape as Christian love and the “highest good” sought by the great philosophers. King incorporated this concept into the nonviolent movement for civil rights, empowering thousands of people to engage in militant, transformative direct action by accepting suffering without retaliation and returning good for evil.”
Well described and, thus, easy to understand. But much more difficult to put into daily practice.