A top Internal Revenue Service official told a Christian group that “Bible teachings are typically affiliated” with the Republican Party as a rationale for denying its application for tax-exempt status.

The Texas-based Christians Engaged filed an appeal on Wednesday to the IRS’ denial, objecting to the tax agency’s assertion that it is partisan.

In a May 18 denial letter, IRS Exempt Organizations Director Stephen A. Martin said Christians Engaged is involved in “prohibited political campaign intervention” and “operate[s] for a substantial non-exempt private purpose and for the private interests of the [Republican Party].”

A “legend” at the top of the letter shows nine letters of the alphabet being used as shorthand to represent something. In this letter’s example, oddly, “D” represented “Republican.”

“Specifically, you educate Christians on what the Bible says in areas where they can be instrumental, including the areas of sanctity of life, the definition of marriage, biblical justice, freedom of speech, defense, and borders and immigration, U.S. and Israel relations,” Martin wrote. “The Bible teachings are typically affiliated with the D party and candidates. This disqualifies you from exemption under lRS Section 50I(c)(3).”

Christians Engaged first applied for tax-exempt status in late 2019. First Liberty Institute, a religious freedom public interest law firm, is representing the Christian group in its appeal.