Since it was published in 1963, Martin’s book ‘Strength to Love’ has been one of my constant companions.  I read it the first time as a teenager trying to understand the insanity of the sixties and seeking to discern where I stood in those days. I have subsequently re-read the book as a guide for living nonviolently. Today, I refer to it as a means for learning how to love.
King used the word ‘strength’ in the title. But what is the strength to love? It is love—the same sentiment we saw in Julian of Norwich. Love is the strength to love. In fact it the only sufficient strength. Any substitute will not fulfil our mandate to love. Martin and those who joined with him in the civil rights movement would never have been able to do and endure if they had not first been filled with the love of God.
This is exactly the witness of Scripture: “We love because God first loved us” (1 John 4:9). Fruit comes from the seed. The fruit of love comes from the seed of love. The heart guides the hand. Intake becomes outflow. Love is the strength to love.
With that in place, King’s book, and even more his life, showed how love proliferates in all directions, influencing every dimension of life. Love gives us a tough mind and a tender heart. It transforms us from conformists into nonconformists. It enables us to be good neighbors. It inspires our actions, to the deepest action—our love of our enemies. Love is the knock at midnight which awakens our conscience and fuels our compassion. Love is the hallmark of our humanity, helping us rise above our shattered dreams and overcome our fears. Love inspires us to live nonviolently in utter confidence that our God is able. 
Those of us who lived through the sixties were inspired by King’s words and his corresponding deeds. And many of us have discovered that the inspiration was not just for those days, but for the days of our lives ever since. In the final analysis, it is the abiding nature of love (John 15:9) that gives us the strength to love.
 Martin Luther King, Jr., ‘Strength to Love’ (Harper & Row, 1963).
 The sentences of this paragraph summarize the book’s chapters, giving us a big-picture view of King’s theology and practice of love.