This week’s allegations of predatory sexual behavior toward children by Alabama Republican Senate nominee, Roy Moore, are suffused with Christmas spirit, and I don’t just mean the detail that one of the 14-year-old girls he propositioned and later “dated” against her mother’s will had been working as a Santa’s Helper at the mall when she first caught his eye.

Incredibly, Moore’s evangelical defenders are turning to the original Christmas story of Jesus’ nativity to explain his behavior in what they claim to be Biblical terms. On Thursday afternoon, Alabama State Auditor Jim Zeigler defended Moore’s actions using Zachariah and Elizabeth, parents of John the Baptist, and Mary and Joseph, who he called the “parents of Jesus.” His statement about Moore is worth quoting in full:

He’s clean as a hound’s tooth. . .Take the Bible. Zachariah and Elizabeth for instance. Zachariah was extremely old to marry Elizabeth and they became the parents of John the Baptist. . Also take Joseph and Mary. Mary was a teenager and Joseph was an adult carpenter. They became parents of Jesus. There’s just nothing immoral or illegal here. Maybe just a little bit unusual.

The 67-year-old Zeigler has been State Auditor of Alabama since 2014. According to Project Vote Smart, he was endorsed by Conservative Christians of Alabama a group he formerly chaired, and which quizzes candidates on such questions as: “Do you support public prayer and Bible reading in Public Schools?” prior to offering their endorsement.

Zeigler’s Bible-believing bona fides would seem to be impeccable, not to mention his intolerance of sexual impropriety among government officials. He filed an ethics complaint against former Alabama Governor Robert Bentley in March 2016 after Bentley was accused of having an extramarital affair with a staffer, claiming at the time that “The governor continues to disgrace the state of Alabama.”

So how exactly does this elder statesman use the original Christmas story to defend pedophilia?

In Luke 1:6-7 we learn of Elizabeth and Zachariah, parents of John the Baptist, that “They had no child, because that Elizabeth was barren, and they were both now well stricken in years.” As Aaron Blake observed in the Washington Post, Elizabeth and Zachariah were both old. This is the point of the story, not that Zachariah was old and Elizabeth was young. Like Sarah, the wife of Abraham, who was too old to have a child when she conceived Isaac, Elizabeth was too old not too young to become pregnant. The parallel stories are about the power of God.

But it is with the Mary and Joseph defense that Moore jumps from a poor reading of the Bible to reliance on an extra-Scriptural Catholic apocryphal tradition. He claims that Mary was a 14-year-old girl and Joseph an older man. Where does he get the idea that Mary was a young teenager? Not from the Bible.

In the Gospel of Luke Mary is described as a “virgin espoused to a man whose names was Joseph, of the house of David.” No age is given for either Mary or Joseph. In the Book of Matthew, chapter 1, the other scriptural source for information about Jesus’ conception and birth, we learn that “the birth of Jesus Christ was on this wise: When as his mother Mary was espoused to Joseph, before they came together, she was found with child of the Holy Ghost” (Matthew 1:18 Authorized King James Version). The tradition that Mary was a teenager and Joseph a much older man comes from an extra-Biblical text, the apocryphal second-century document, the Protoevangelium of James.

The Protoevangelium is the source of much traditional Catholic knowledge about Mary and includes the only mention of her parents, Anna and Joachim, who are both Catholic saints. The Protoevangelium is concerned, beginning to end, with preserving the perpetual virginity of Mary, not the virgin birth. In fact in the text a midwife who doubts that Mary could remain a virgin even during birth performs a quick pelvic exam on her, only to have her hand burst into flames for her unbelief. Both Matthew and Luke affirm that Mary conceived Jesus while a virgin, but unlike the Protoevangelium they do not imply that she remained a virgin forever. All the gospels mention Jesus’ brothers or adelphoi (who Catholics insist were his cousins or spiritual brothers).

Despite lack of canonical evidence, the preoccupation with preserving Mary’s perpetual virginity is almost as old as the Gospels themselves. In addition to the anecdote about the midwife, in the Protevangelium also reveals details about Mary’s childhood and how Joseph became her spouse. In the story, Mary was taken by her parents to the temple at age three where she lived with handmaidens and was fed by angels until she turned twelve. The onset of her adolescence meant that she would have to leave the temple and that a suitable husband would have to be found for her. So all the widows of the region were assembled and brought with them their rods and staffs. When Joseph’s rod was chosen by lottery, a dove flew out of it and landed on Joseph’s head, a sign that he had been chosen by God.

At first he demurs, claiming “I have children and I am an old man, and she is a young girl, I am afraid lest I become a laughing-stock to the sons of Israel.” But the high priest warns him he will be punished if he does not accept the will of God, so he reluctantly agrees to take young Mary as his wife.

Protestants like Zeigler have traditionally been much less interested in Mary and Joseph than Catholics have, and many believe that Mary was only a virgin until she gave birth to Jesus. After that, she would presumably have had a normal sex life with her husband. Zeigler’s creepy defense of Moore’s predatory behavior does not, as some have implied, threaten the Christian doctrine of the Virgin Birth, but the Catholic doctrine of Perpetual Virginity.

The Protoevangelium implies that Joseph the older man is chosen by God to be Mary’s husband precisely because he could be trusted not to violate the young child’s body. Because of his age and maturity (old enough to be Mary’s father) he among all the widows of Judea would protect Mary, the innocent child. It is striking that Zeigler, the Alabama Bible-believing evangelical relies on an extra-biblical-to-Catholic legend to defend Roy Moore—one that arose, ironically, because of the assumption that young girls can be expected to be protected by older men, not preyed upon by them.

While Moore’s campaign may call the Washing Post’s revelations a “last ditch Hail Mary” attempt to discredit him, it is his Christian defenders who are using Roman Catholic beliefs about Mary in the most disturbing of ways.