MANTI — A purported doomsday cult leader from Cedar City told a judge Wednesday he hoped to have a family and grow old with an 8-year-old girl he considered his bride.

"I sincerely believed that child marriage was a correct principle from God. And I've seen the consequences of what's happened, and I know that I shouldn't have done it now," said Samuel Warren Shaffer, 35. "But I sincerely believed that the practice was correct at the time."

He added that the girl seemed happy and that he believed he was not hurting her.

Judge Marvin Bagley sentenced Shaffer to prison for at least 15 years and up to life moments after Shaffer pleaded guilty to one count of child sodomy, a first-degree felony, in Manti's Sixth District Court.

"I'm not aware of any religion in this world that justifies an adult having a sexual relationship with an 8-year-old girl," Bagley said. "Certainly it's a violation of Utah law."

Shaffer and 34-year-old John Alvin Coltharp, another alleged leader of the religious group called the Knights of the Crystal Blade, believed they had wed each other's daughters, investigators said. Prosecutors have characterized the group as an online-based "fundamentalist group for Millennials."

Investigators began looking for Shaffer and Coltharp after they disappeared with their daughters in September. In December, an Amber Alert was issued after police said they learned more about what the men were doing. Coltharp's daughters, ages 5 and 7, and Shaffer's daughters, ages 4 and 8, were found hidden away in frigid temperatures in a remote area of Iron County. Two were tucked in plastic barrels and the other pair in an abandoned mobile home. They were not dressed for the cold and had no food or water, investigators said.

Shaffer in the Wednesday hearing said he previously "had romantic interest" in the girl, but he now loves her in the sense that he cares about her wellbeing.

"If you have that concern for her wellbeing and care about her, why did you do what you did?" the judge asked. Shaffer emphasized that he believed child in marriage at the time.

"I want her to know that it's OK and I love her and I never want her to feel guilty about it. I want her to be happy," he said.

In exchange for Shaffer's guilty plea to the one sodomy charge Wednesday, an additional child sodomy count was dismissed. Other charges that were dropped Wednesday included bigamy and obstructing justice, second-degree felonies; and lewdness involving a child, a misdemeanor.

The judge allowed Shaffer's new prison sentence to run at the same time as a different, longer prison term he is now serving in connection to the abuse that occurred in Iron County. In May, a 5th District judge sentenced him to at least 26 years and up to life in prison for rape of a child, a first-degree felony, and child abuse, a second-degree felony.

The sentence imposed Wednesday won't extend Shaffer's prison term, but it will appear on his record to be reviewed by parole officers when they consider whether to release him, prosecutors said.

Outside the courtroom, Sanpete County Attorney Kevin Daniels said Shaffer's explanation displayed "some pretty twisted thinking."

"I believe it's case closed," Daniels said. "Sexual abuse in and of itself causes a lot of damage, but when it's done under the auspices of religion, it makes it even worse. It's egregious."

Testimony that Shaffer gave earlier in the case against Coltharp spared the girls from testifying, he added. Coltharp, of Spring City, pleaded guilty to sodomy and child bigamy felony charges in Manti earlier this month. His sentencing is scheduled for August 8.

An alleged follower of the group, Robert Shane Roe, 34, of Castro, California, also faces a child sodomy charge. He made his initial appearance in Manti last week and is next due in court July 18.

Those who have experienced sexual abuse or assault can be connected to trained advocates through Utah's statewide 24-hour Rape and Sexual Assault Crisis Line at 888-421-1100.