Former U.S. Secretary of State Hillary Clinton is a candidate for the Democratic nomination for president. The opinions expressed in this commentary are hers.

One year ago today, our nation lost nine precious lives . They were mothers and fathers, students and coaches, pastors and choir members. They were men and women of faith, each filled with passion and love, and with so much left to give. For many, time has done little to dull the pain of their loss. I still remember my grief and confusion when I heard the news. But their deaths have not been in vain.

"Love bears all things, believes all things, hopes all things, endures all things," Scripture teaches us. "Love never fails."

On that evening in the "Mother Emanuel" AME Church , Clementa, Cynthia, Susie, Ethel, DePayne, Tywanza, Daniel, Sharonda and Myra lived out the lessons of their faith, like always -- welcoming a stranger for prayer and fellowship, offering love without a second thought.

Their spirit of love remained long after they were gone. In court, one by one, grieving parents and siblings looked at the young man who had taken so much from them and said, "I forgive you." And the entire Charleston community -- black and white, Christian, Muslim and Jewish, and so many others -- came together to stand up to hate and bigotry, providing love to one another instead.

Filled with that love, we have made progress. The Confederate flag that flew on the South Carolina State House grounds has been removed. Young people have called out for much-needed reforms to our criminal justice system. Mothers who lost their children to gun violence are channeling their grief into action and turning their mourning into a movement for common-sense gun reform.

But we have much more to do.

Another mass shooting, in Orlando , broke our hearts earlier this week. An average of 90 people a day are killed by gun violence in our country. This must stop. A good first step is closing the "Charleston Loophole" in our gun laws, which allows a person otherwise prohibited from buying a gun -- such as a domestic abuser or other violent criminal -- to buy one if a background check isn't completed within three business days. This loophole allowed the alleged Charleston shooter to buy his gun despite his prior arrest record. How many more innocent people need to be cut down before we act and close this dangerous loophole?

On that terrible evening and every day since, Americans across the country have joined our hearts with the people of Charleston and South Carolina. Millions of Americans are still walking with them -- in grief, solidarity and determination.

In the spirit of the Charleston Nine , let's bridge our divides, fight for change and remember that love never fails.

With solidarity and warm regards, I am

Sincerely yours,

Hillary Rodham Clinton