SAN ANGELO, Texas — Prosecutors played an audio recording Tuesday of a polygamist sect leader instructing his 14-year-old “spiritual wife” on how to please him sexually, and thus please God.

Warren Jeffs, 55, is head of the Fundamentalist Church of Jesus Christ of Latter Day Saints, which believes polygamy brings exaltation in heaven. He is accused of sexually assaulting two girls, ages 12 and 15, who he took as brides in “spiritual marriages.”

A doctor and a forensic analyst testified Monday that Jeffs was the father of the 15-year-old’s child. Prosecutors played the tape of Jeffs talking to the girl when she was 14 after Texas Ranger Nick Hannah testified about documents and electronic files seized during a 2008 police raid at the church’s remote compound in West Texas.

Among the documents seized was a record of Jeffs’ spiritual marriage “for time and all eternity” with the 14-year-old in January 2004. An excerpt from hundreds of pages of Jeffs’ personal journals said the child was “pure and innocent and willing to obey.”

Hannah read from Jeffs’ journals, which said he took the 14-year-old and another of his new wives on a car ride outside the church’s headquarters along the Utah-Arizona border for “training.” There, he instructed them on their responsibilities as his wives and had the session taped.