The ease and openness with which Democratic presidential hopefulPete Buttigieg talks about his religious beliefs appears to be causing consternation among some conservative Christians. Evangelical Christians have long seen themselves as the standard-bearers for faith and family values in American politics. Buttigieg, a gay Christian, is directly challenging that, driving some evangelical leaders to try to paint his faith as an inauthentic expression of Christianity. Franklin Graham, son of the famed evangelist Billy Graham and a supporter of President Donald Trump, criticized the faith of the South Bend, Indiana, mayor ― and progressive Christianity as a whole ― on Twitter and Facebook Thursday. “We don’t define sin, God does in His Word,” tweeted Graham, who has long maintained that queer love is a sin. “Using new terms like ‘Progressive Christianity’ & ‘Christian Left’ may sound appealing, but God’s laws don’t change. I believe what the Bible says is truth.”

God loves us, & the Bible says we're all sinners who need God’s forgiveness. We don’t define sin, God does in His Word. Using new terms like “Progressive Christianity” & “Christian Left” may sound appealing, but God’s laws don't change. I believe what the Bible says is truth. 3/3 — Franklin Graham (@Franklin_Graham) April 11, 2019

Graham was responding to Buttigieg’s criticism of Vice President Mike Pence, a former governor of Indiana, earlier this week. Buttigieg had said Sunday that “the Mike Pences of the world” should realize that “if you’ve got a problem with who I am, your problem is not with me. Your quarrel, sir, is with my creator.” Pence characterized Buttigieg’s comments as an attack on his faith. The vice president told CNN on Friday that he is a “Bible-believing Christian” who draws his truth “from God’s word.” Buttigieg fired back by saying that he’s not critical of Pence’s faith but is concerned about his anti-LGBTQ policies. “I don’t have a problem with religion. I’m religious, too,” Buttigieg said on “The Ellen DeGeneres Show” on Friday. “I have a problem with religion being used as a justification to harm people.” Robert Jeffress, pastor of First Baptist Dallas and an evangelical adviser to Trump, argued on Todd Starnes’ radio show that some liberals are serving a “God of their imagination.” The conservative columnist himself wrote that Buttigieg “wants to shove Evangelical Christians into the closet.”

If Pete Buttigieg has problem w/@VP belief in traditional marriage, his quarrel is w/Jesus who said “From the beginning God made them male and female...For this cause a man shall leave his father & mother & shall cleave to his wife, & the two shall become one flesh (Matt. 19:4-5) — Dr. Robert Jeffress (@robertjeffress) April 8, 2019

Conservative evangelical writer Erick Erickson has been tweeting and blogging about Buttigieg’s faith this week, contending that the mayor “does not understand the roots of Christianity” and wants to reject parts of Christian teaching that “might make his life a bit uncomfortable.” Erickson also said that progressive Christianity is a “hypocritical farce.” He denigrated the Episcopal Church, the denomination that Buttigieg belongs to, claiming that it is “no longer a Christian institution.”

I mean if Buttigieg thinks evangelicals should be supporting him instead of Trump, he fundamentally does not understand the roots of Christianity. But then he is an Episcopalian, so he might not actually understand Christianity more than superficially. — Erick Erickson (@EWErickson) April 7, 2019

In recent years, the Episcopal Church, along with a number of other mainline Protestant denominations, has adopted affirming stances toward LGBTQ Christians, ordained LGBTQ clergy and allowed priests to perform same-sex marriages. Eleven U.S. presidents have been Episcopalian. Erickson wrote that his major problems with Buttigieg are the mayor’s positions on abortion and the right of businesses to refuse service to queer customers. It’s fine for Christians to vote for gay people, Erickson stated, “just as they can vote for someone who is three-times divorced and cheats on his wives with porn stars.” “Christians should go with the moral person, but in the absence of that moral person, I do not think they have to abandon politics when one of two candidates takes positions that support life and allows Christians to live their faith publicly and the other is openly hostile to the faith of orthodox, Bible believing Christians,” he wrote on Tuesday. However, some equally devout Christians reading the same Bible have come to radically different conclusions about what orthodox Christianity demands.

Ethan Miller via Getty Images Presidential hopeful Pete Buttigieg speaks at a meet-and-greet at Madhouse Coffee on April 8, 2019, in Las Vegas.

Ethan Miller via Getty Images Buttigieg talks to members of the media outside Madhouse Coffee on April 8, 2019, in Las Vegas.