In 1976, Jimmy Carter said something almost never before uttered in American presidential politics. During the Democratic primary this year, Carter mentioned to some reporters that he was an evangelical and a “born-again” Christian.

These words prompted the media to find out what Carter meant. What is an evangelical, they asked each other?

Shortly thereafter, New York Times reporter Kenneth Briggs gave his readers a lengthy explanation, suggesting that the ignorant press—not the credulous Carter—was the oddity in American life. Noting that some 40 to 50 million Americans also identified themselves as evangelical at the time, Briggs noted that Carter’s faith “was not only widespread but also growing faster than any other Christian perspective.”

Now, nearly 50 years later, it is hard to imagine a time when being evangelical or speaking openly about one’s religious beliefs would be viewed as a liability for a presidential candidate, as many thought it was for Carter in 1976. Such things have become standard in American politics. And for Republicans who want to make it to the White House, they are almost a requirement. When someone like Mike Pence says he is “a Christian, a conservative and a Republican, in that order,” the former vice president knows he is speaking in the language the GOP’s white, evangelical base expects from its candidates.

Pence speaks from a script originally written by Jimmy Carter, the nation’s 39th president, who died Dec. 29 at the age of 100. “The most important thing in my life is Jesus Christ,” Carter said at a campaign stop in 1976. By making his personal faith a central aspect of his self-presentation to voters, Carter helped bring religious themes to some extent into the American presidency to bring something that had never been seen before.

Carter, a devout Southern Baptist who taught Sunday school, simply spoke authentically about himself. He also knew that his portrayal of himself as a moral and religious man in the wake of the Watergate scandals would reassure many Americans who had lost faith in the institutions of the United States country, especially in the government. “I will be a better president because of my deep religious convictions,” Carter assured Americans.

But this was neither a self-righteous boast nor a threat. Instead, Carter said he understood that his Christian faith compels him to live a life of service to others, especially those whom the Bible commands Christians to help: the poor, the sick and the marginalized.

At the same time, Carter’s presidency coincided with and helped solidify the rise of politically active white evangelicals in the late 1970s. When he ran for president in 1976, Carter rode the wave of their enthusiasm to the White House. Nearly 60% of Southern Baptists voted for Carter in 1976, the first time a majority voted for a Democratic presidential candidate since 1948 — and the last time that happened.

As president, Carter took different positions on controversial social issues than Southern Baptists and other white evangelicals would likely have expected from a fellow believer. During the campaign he had expressed his moral opposition to abortion but said he would not seek to repeal the law.

This attitude was anything but progressive. But conservative Christian pastors and religious right leaders argued at the time that abortion was one of the most important political issues, and they questioned whether Carter was a true Christian if he was unwilling to advocate for abortion.

On gay rights, Carter took a bolder course. Carter indicated he would sign a gay rights bill, and he spoke out against an anti-gay ballot initiative in California. (Ronald Reagan did, too.) In the summer of 1980, with the election just months away, his White House hosted the family conference. The name reflected organizers’ view that Americans belonged to families of all stripes, including same-sex households. The Southern Baptist Convention, Carter’s own denomination, passed a resolution condemning the conference for “undermining the biblical concept of the family.”

These positions sparked outrage among many conservative Christians about the Carter presidency. Their anger highlighted the gap between Carter’s faith-based sense of public service and the emerging religious right’s view that she could use politics to impose her beliefs in the public square. It also drove white evangelicals to stay in the Republican Party.

Jerry Falwell, the late fundamentalist televangelist, spurred this development by creating the Moral Majority. The right-wing religious organization worked with evangelical churches across the country to mobilize conservative Christians and register new voters. Falwell later claimed that his group had mobilized 4 million first-time voters—and motivated millions more—to vote for Reagan over Carter.

Furthermore, in a presidential election, Falwell had brought social issues to the fore, infusing them with the language of religion and morality. Reagan played along, echoing the religious right’s views on abortion and gay marriage, as well as things like school prayer and sex education. And he presented the Bible as a black and white guide to how things should be done.

“Indeed, it is an undeniable fact,” Reagan told a crowd of 15,000 evangelical clergy in Dallas shortly before the 1980 election, “that all the complex and terrible questions we face at home and around the world have an answer in this single book find.”

Falwell and Reagan are credited with transforming the nation by helping to solidify the Republican Party’s religious right and secure its place in American politics. But Falwell and Reagan—and many subsequent Republicans, including President George W. Bush—also followed in Jimmy Carter’s footsteps, even as they led the nation down a very different path.

Carter spoke openly and honestly about his faith, hoping to show the country that he could be trusted and that his religious beliefs would guide his actions as president. But by making religious belief part of presidential policy, Carter also opened the door to other uses of religious belief in public life.