Updated

Forty-five years later, the violent death of Martin Luther King Jr. throws into stark relief his message of nonviolence.

His youngest daughter and other Christian leaders say they need to spread the message again to a nation struggling to explain and prevent a tragedy like the Newtown school shooting.

Bernice King, who is chief executive of the King Center in Atlanta, recalls a sobering statement from her father. He once said: "The choice is no longer between violence and nonviolence, but nonviolence and nonexistence."

She thinks churches and preachers need to be proactive in spreading the nonviolence message from the pulpit and through education.