James B. Comey, the former FBI director, joined Instagram on Friday. And his first post is basically a biblical subtweet.

Some context: Comey was the director of the FBI until May, when President Trump fired him, giving explanations that alternately said his firing was or was not related to the ongoing investigation into whether Trump’s campaign colluded with Russia.

Since then, Comey has from time to time made his presence known on Twitter — often with a religious bent. He used to tweet anonymously, under the name of Reinhold Niebuhr, a theologian whom Comey wrote his college thesis about.

When a journalist blew his cover, Comey admitted that the Niebuhr account was his, and eventually changed its name to his own. His tweets tend to coincide with events in the Trump administration, to the point that he’s been called a “Twitter prophet.”

On Friday, the news was the guilty plea of Michael Flynn, Trump’s former national security adviser, for lying to the FBI about his conversations with the Russian ambassador. And Comey responded to it not by naming Flynn, but posting a photograph of running water, accompanied by the words that Comey, a Methodist, has previously described as his favorite Bible verse: “Let justice roll down like waters and righteousness like an ever-flowing stream.”

Those words from the Old Testament prophet Amos are not necessarily surprising for the favorite verse of a longtime employee of the Justice Department. The verse was a mainstay during the Civil Rights movement; the Rev. Martin Luther King Jr. famously spoke it during his “I Have a Dream” address from the steps of the Lincoln Memorial.

“We cannot be satisfied so long as the Negro in Mississippi cannot vote and the Negro in New York believes he has nothing for which to vote. No, no, we are not satisfied and will not be satisfied until justice rolls down like water and righteousness like a mighty stream,” King proclaimed.

Comey wasn’t the only one to turn to religion in light of Friday’s news. Flynn himself said, in his statement about his guilty plea, that while he maintains that accusations of treason on his part are false and painful, “I recognize that the actions I acknowledged in court today were wrong, and through my faith in God, I am working to set things right.”

Former FBI chief James B. Comey put an end to online rumors when he confirmed Oct. 23 that he is the owner of a Twitter account with the name Reinhold Niebuhr. (Taylor Turner/The Washington Post)

Want more stories about faith? Follow Acts of Faith on Twitter or sign up for our newsletter.