"But dwell for another moment on that final paragraph of Lincoln’s 1846 handbill. It’s one thing, Lincoln says, to be an unchurched man; that he is, and he admits he is. It’s another thing to be “an open enemy of, and scoffer at, religion.” For to be such a man is to “insult the feelings, and injure the morals, of the community.” For all the differences there might be among Christian denominations—differences that remind us that the freedom to differ in belief, and even to disbelieve, is essential—there is, Lincoln seems to be saying, an intimate relation of the people’s religious beliefs to their morals and their feelings. The man who mocks or disregards the first harms the second and wounds the third. He is not to be honored by being made the people’s representative.
This is not about imposing a formal “religious test” for serving in office, of the kind that Article VI of the Constitution forbids; Lincoln is not advocating that. It’s not even about what the candidate himself—such as Lincoln—actually believes. It’s about the trust that must obtain between officeholder and constituents. Lincoln here affirms that the American people are a religious people, that their religion does great good, and that they should be represented by leaders who recognize and honor their faith and the sensibilities that arise from it."