Millions of Christians in churches around the world heard the same passage on Sunday from the Gospel of Luke. In it, Jesus declares his intentions “to proclaim good news to the poor,” as he speaks to people gathered in a synagogue in Nazareth.

At Episcopal Church of the Transfiguration in Dallas, the passage felt particularly appropriate this week, though it was chosen years ago as part of a three-year cycle of Bible readings.

“It’s Jesus 101,” said Michelle Williams, 55, a parishioner at the church.

It was the first Sunday since a fellow Episcopalian, Bishop Mariann E. Budde, delivered a sermon that many observers heard as an echo of passages like the one from Luke. Speaking at a prayer service at the National Cathedral in Washington the day after President Trump’s inauguration, she faced the president and made a direct plea: “Have mercy.”

After the service, Mr. Trump called Bishop Budde a “Radical Left hard line Trump hater” in a social media post. His foes immediately hailed her as an icon of the resistance. But for many progressive Christians and their leaders, the confrontation was more than a moment of political catharsis. It was about more than Mr. Trump. It was an eloquent expression of basic Christian theology, expressed in an extraordinarily public forum.

Sara Ivey, 71, another parishioner at Church of the Transfiguration, said the sermon reminded her of Psalm 103, which describes God as “merciful and gracious, slow to anger and abounding in steadfast love.” The sermon, which she watched live, made her “very proud to be an Episcopalian,” she said.