‘This whole week,” said President Obama, “I’ve been reflecting on this idea of grace.”

That was the turning point of Friday’s eulogy for Clementa Pinckney, the Charleston, South Carolina, minister who was, with eight of his congregants, murdered by a racist terrorist two weeks ago. It was the moment a memorable speech became a speech for history.

“According to the Christian tradition,” the president-turned-preacher explained, “grace is not earned, grace is not merited, it’s not something we deserve.

Rather, grace is the free and benevolent favor of God.” Grace, in other words, is that which bridges the gap between creation and Creator, the staircase connecting the soil to the celestial.

And it is amazing. So the heart leapt when, moved by some ephemeral thing cameras could not see, Obama launched into a soulful, heartfelt and, yes, off-key rendition of one of the foundational hymns of the church.

“Amazing grace,” he sang, 6,000 voices rising to meet him, “how sweet the sound, that saved a wretch like me. I once was lost, but now am found, was blind but now I see.”

“As a nation, out of this terrible tragedy,” the president said, “God has visited grace upon us, for He has allowed us to see where we’ve been blind. He’s given us the chance, where we’ve been lost, to find our best selves.”

The president named a few of the things to which we’ve been blind, the issues upon which we have been lost. He spoke of gun violence, the hunger of children, the brazen hatred that inspired the alleged shooter, the soft bigotry that gets “Johnny” called back for an interview but leaves “Jamal” job hunting.

Though he didn’t mention it, it seemed not inconsequential that he said these things on the same day the Supreme Court affirmed the right of same-sex couples to marry.

It seemed fitting that he returned that night to a White House bathed in colors of the rainbow. One could almost see history making a great, wide turn toward freedom.

And, too, one heard predictable howls of outrage. Sen. Ted Cruz called it one of the darkest days in American history. Rush Limbaugh predicted polygamy. Some Southern states, as they did during the civil rights years, declined to be guided by the court’s ruling. But it all carried a tinny, faraway sound, like a radio station from some distant town, drowned by the thunder of rejoicing.

This is not to say those doorkeepers of yesterday are without power to interdict change. They are nothing if not stubborn and resilient. It is, however, to say that the arc of the moral universe is long, but it bends toward justice.

And, moreover, that the genius of the nation founded 239 years ago Saturday by a group of men we would now call sexist, racist and homophobic, was not its perfection as originally conceived, but the fact that it was built for change, built to become better, and continually expands itself to accommodate that long arc.

Are we not tasked with forming “a more perfect union”? It’s the ongoing work of America, work no one speech or court ruling can finish, but which we are all charged with pushing forward. Until one bright day, you look up and are surprised how far you’ve come.

That’s what happened Friday. And it might be the story of John Newton’s life. Newton, who wrote the hymn in which President Obama found solace, was a slave trader who changed by increments over the years until, by the end of his life, he was issuing grief-stricken apologies for his part in that evil business.

If the first verse of his hymn is a paean to the redemptive power of grace, its third is a reminder that grace obligates us to push forward toward bright days not yet glimpsed:

“Through many dangers, toils and snares,” he wrote, “I have already come,

” ‘Tis grace has brought me safe thus far

“And grace will lead me home.”

Leonard Pitts is a Pulitzer Prize-winning columnist for The Miami Herald. He can be contacted at:

lpitts@miamiherald.com