Agape love is the central premise of Protestant Christian theology. According to The Oxford Handbook of Theological Ethics, “Luther’s rediscovery of the primacy of agape was the linchpin of the Reformation and the rediscovery of genuine Christian ethics.” (See G. Meilaender and W. Werpehowski, The Oxford Handbook of Theological Ethics, 2007, p. 456.)
Many confuse the concept of agape love with the concept of caritas, or charity, but these are two separate ideas. The concept of agape love is the love of God reaching down to save humanity through grace, while caritas is about humans reaching upward toward God through works.