Republican presidential hopeful Sen. Marco Rubio is dealing with skepticism from Iowa religious voters regarding his position on gay marriage.

Rubio’s campaign is trying to court evangelical Christians, a powerful voting bloc that polls show favors Republican candidates Ben Carson, Sen. Ted Cruz, and Donald Trump.

Many ministers are reortedly skeptical of Rubio because they’re unsure whether Rubio’s views are in line with the teachings of the Bible when it comes to the issue of gay marriage. Some Iowa pastors say they want “to know Rubio’s authentic feelings about gay rights.”

According to Des Moines Register:

They had questions about reports that he has courted gay conservatives with the Log Cabin Republicans; why he thinks “sexual preference is something that people are born with,” as he said on CBS’s “Face the Nation” in April; why he implied in his statement on the U.S. Supreme Court case on marriage that the issue is settled

Some pastors expressed their concern with Rubio’s ties to Paul Singer, a billionaire who has funded the fight for gay marriage. Singer is now a major donor to Rubio’s presidential campaign and the founder of a super-PAC whose purpose is to help make the Republican Party pro-gay marriage.

Other pastors, “told the Register they were looking for proof of Rubio’s adherence to Biblical principles, including statements on how far he’s willing to go to fight the U.S. Supreme Court’s June ruling that legalized same-sex marriage.”

Rubio’s record on gay marriage is rightfully causing concern, especially after the Obergefell v. Hodges supreme court case. As Breitbart News has pointed out:

After the Obergefell decision imposing gay marriage on the county, a decision law professors have called illegitimate, Gallagher gave Rubio a “D.” Writing at The Pulse2016 blog published by the American Principles Project, Gallagher complained that Rubio issued only a pro forma statement and “ran away…” She said he promised to protect First Amendment freedoms but “laid out no concrete steps for doing so.” Rubio is on record opposing a constitutional amendment to enshrine man-woman marriage. He says, “It is what it is and that’s what we’ll live under.”

The evangelical voters that spoke to Des Moines register praised Rubio for his ability to communicate, but were skeptical of whether his words will ever translate into action on issues they feel passionate about, such as abortion.

Jane Jech, a former worship director at New Hope Christian Church in Marshalltown told the register that she thinks Rubio is “very gifted with words” and “knows how to word things carefully.” She added that she believes that Rubio is pro-life. However, she said that, “as president I’m not sure what action he would actually take,” she said.

According to a recent Quinnipiac University poll, Sen. Ted Cruz (R-TX) is the most popular republican presidential candidate among white evangelical voters, holding 27 percent of their support. Ben Carson is right behind with 24 percent, followed by Donald Trump with 20 percent. Rubio currently only holds 8 percent of their vote.