At the time of the Rev. Martin Luther King Jr.’s death in 1968, his voice was everywhere. The civil rights movement in America moved to the pulse of his cadences.

Among the many laments after King’s assassination was the poignant realization that we would no longer hear that voice. Moved by that melancholy silence, I set out to write a book about King the preacher.

In library basements and other quiet places, I listened to crackling tapes of his sermons at Ebenezer Baptist Church in Atlanta, where he preached on average two Sundays a month. I became a parishioner in earphones. Hardly a Sunday passed that King did not remind us that we are children of God, made in his image and deserve to be treated as such.

I was listening to the first draft of King’s vision for America.

Decades later, my private epiphany has grown into a matter of public urgency. Lying has become the new normal, and racism a matter of public policy. Meanwhile, aside from the annual MLK holiday and the recent Super Bowl commercial, we rarely hear King’s voice anymore.

We have no one of his stature to set the mark sufficiently high for us — to illumine our national sins, inspire us with hope or tell us who we are as a people. Within the nationally prominent Black Lives Matter movement, no single voice has emerged to lead the way as King did.

King spoke powerfully from the great tradition of the black church. Today, his preacher-led movement seems somewhat out of step with the more secular approach of the activists leading the way 50 years later. So much so that it’s easy to overlook the powerful links between them.

King understood that our political life must be governed by something larger than politics, or we are lost. When a black church in Georgia was firebombed, King and his associates would rush to the scene. In his white shirt and dark suit, Bible tucked under his arm, he would stride into the smoldering remains and preach from the ashes.

It was his way of symbolizing the triumph of a people and the word of God over every attempt to destroy them. Like President Barack Obama’s sermon after the attack in a Charleston, S.C., black church, it was his way of asserting a moral reality larger and more authoritative than guns, hate or the lies of white supremacy.

King’s activism ran on meaning — rife with symbolism in its marches, hymns and public prayers. It was a metaphoric movement that achieved tangible legislative results, where a march, lunch counter and even a jail stood for other, transcendent realities.

Before Twitter and Facebook, King’s preacherly style was expected. The black church had always been an incubator of charismatic leaders. In places like Selma, Ala., or Albany, Ga., King’s physical body was a required presence, like a sacrament.

Social media has created a thousand points of autonomy, and the old totems are no longer necessary or welcome.

It has galvanized those who were ignored or underrepresented in King’s movement, including women, gays, transgender people and the undocumented. “The central contradiction of the civil rights movement,” wrote Jelani Cobb in the New Yorker, “was that it was a quest for democracy led by organizations that frequently failed to function democratically.”

Civil rights protests in the ’60s were dramatic interruptions of regularly scheduled programming, and their principal actors were stars. Most of today’s civil rights leaders do not make speeches for the ages. They have not had a dream or been to the mountaintop. The founders of Black Lives Matter, Alicia Garza, Opal Tometi and Patrisse Cullors, are not household names like King, Jesse Jackson, Ralph Abernathy and Andrew Young. Like Ella Baker before them, they work hard and mostly anonymously.

In contrast to the civil rights movement decades before, Black Lives Matter is marked by a spare integrity of language. Like the Puritans’ plain speech, leaders express the facts of black existence apart from the distractions of rhetoric or religion. Even the phrase “black lives matter” uses understatement to make a claim so inarguably true that it should be obvious to all.

King, who by the end of his life was moving in the direction of Malcolm X, would have been more than okay with Black Lives Matter. Despite the glories of his rhetoric, King had a visceral streak of anger that raged against the senseless waste of black life. It prompted journalist David Halberstam to dub King “the angriest man in America.”

Like an Old Testament prophet, he could decree, “Our nation was born in genocide,” and trace the sins of the fathers to the present generation. King’s anger became the percussive partner to his more famous hope — and to his sorrow.

In his last sermon, preached at Washington National Cathedral in Washington, King spoke of children living with rats in Newark and of country people in Marks, Miss., foraging for food. Then comes a moment in the sermon when he pauses as if transported back to Newark or Mississippi and, with a sigh too deep for words, says simply, “Poor people.” He lets the words stand alone, unadorned. He leaves the pretty metaphors behind.

King’s move to Chicago radicalized him. In the North, they played a different kind of hardball. In one of his final essays he complained of “an aggressively hostile police environment.” In words that could have been written the morning after Ferguson, he continued, “police must cease being occupation troops in the ghetto and start protecting its residents. Yet very few cities have really faced up to this problem and tried to do something about it. [Policing] is the most abrasive element in Negro-white relations.”

Toward the end of his life, King enlarged his vision to include poor people of all races and cultures. To dramatize their plight, the preacher was planning a Black Lives Matter-type disruption of traffic and daily life in Washington. He was about to take a dangerous step away from the implicit boundaries of his earlier campaigns.

Much has changed in our national life in 50 years, but the Bible’s proverb is truer today than ever: Where there is no vision, the people perish.

King understood that better than any public person in recent memory. He was our nation’s visionary, our teacher. He modeled how to speak to those with whom we disagree and how to respond to hate. He taught us how to get angry. He gave us a new language for hope. And of course, he offered a better dream for America.

At the Lincoln Memorial, King wasn’t dreaming of a utopia. He asked us to believe that we are, or could be, one people. As visions go, it was minimalist in scope. The dream was a point of departure, a place to begin.

With similar modesty, the sentence “black lives matter” is a minimalist manifesto, requiring us only to acknowledge the human worth of others. But when that minimum is achieved, everything is possible.

On that, King and his radical successors would agree.

Richard Lischer taught for many years at Duke Divinity School. The second edition of his book, “The Preacher King: Martin Luther King Jr. and the Word that Moved America” will be published by Oxford University Press later this year.