YEARS ago, members of a Southern Baptist church in suburban Birmingham, Ala., who couldn’t figure out why their church was in decline asked a friend of mine for advice. The area had been majority white during the violent years of Jim Crow. While civil rights protesters were beaten and children were blown apart by bombs, church members had said nothing. That would be “political,” church members said, and they wanted to stick to “simple gospel preaching.”

As the years marched on, the area became majority black. The congregation dwindled to a small band of elderly whites who now lived elsewhere. They tried, they said, to “reach out” to the church’s African-American neighbors, but couldn’t get them to join.

A canvass of the area would have told them that the church had already sent a message to those neighbors when it had stood silent in the face of atrocity. Those neighbors now had no interest in bailing out a congregation with a ministry too cowardly to speak up for righteousness when it had seemed too costly to do so.

As of this week, the nation faces a crazier election season than many of us ever imagined, with Donald J. Trump as the all-but-certain nominee of the Republican Party. Regardless of the outcome in November, his campaign is forcing American Christians to grapple with some scary realities that will have implications for years to come.