( CNN ) -- Court officials have released the chilling audiotapes that prosecutors say depict convicted child rapist Warren Jeffs training the girls he claimed were his `` spiritual wives '' to have sex with him . The audiotapes , that were key pieces of evidence in Jeffs ' trial , brought some jurors to tears during Jeffs ' trial . Last week , a Texas jury sentenced Jeffs to life in prison for aggravated sexual assault of a 12-year-old girl and 20 years in prison for the sexual assault of a 15-year-old girl . Jeffs , 55 , had perverted his position as the head of the Fundamentalist Church of Jesus Christ of Latter-day Saints to `` satisfy his own personal appetites and desires , '' prosecutor Eric Nichols said . Jeffs talks about those desires on audiotapes that authorities seized from his car and the church 's Yearning For Zion Ranch compound in Eldorado , Texas . The tapes , that were obtained by many media outlets including the Salt Lake Tribune and CNN affiliate KSTU on Thursday , contain what prosecutors say is evidence of Jeffs instructing underage girls to have sex with him . At one point , Jeffs is heard saying God instructs `` for quorums of wives to be with me , to assist me . To be a comfort . Yes , even physically . '' Several times , Jeffs refers to having sexual relations with him as `` heavenly sessions , '' and he instructed the young ladies that they also `` must assist each other '' during these sessions . `` You have to know how to be excited sexually , '' Jeffs said . `` The Lord has intended that my ladies , all of my ladies be trained . '' During Jeffs ' trial , an FBI agent read from a journal that Jeffs kept in which prosecutors say prove he knew his behavior would be frowned upon . Jeffs allegedly wrote : `` Things are happening so quickly . There is an even younger girl that the Lord wants me to take . She is 13 . For some reason , the Lord is sending me these girls that can be worked with . '' Jeffs also wrote : `` If the world knew what I was doing , they would hang me from the highest tree , '' according to evidence presented in court .
The tapes were key pieces of evidence in the sexual assault trial of Warren Jeffs . Jeffs , a polygamist sect leader , was convicted of sexually assaulting a 12 and 15-year-old . Jeffs refers to having sexual relations with him as `` heavenly sessions '' 'The Lord has intended that my ladies , all of my ladies be trained , '' Jeffs says .