"We don't want the child to have to deal with issues that might arise when the parents feel one way and the expectations of the church are very different," he said, noting that "nothing is lost to them in the end" if these children join the faith when they become adults.
Christofferson said the church made the shift largely as a reaction to the Supreme Court's decision legalizing same-sex marriage nationwide. The faith acknowledges the law but "not as a right that exists in the church. That is the clarification."
Stuart Reid, a former public relations employee of the LDS Church and twice a bishop, believes the policy shifts and the subsequent debate are necessary.
"These are the times when people in the church are confronted with the choice of being politically correct or being prophetically correct," he said Friday. "In other words, they have to choose where they stand and what they are going to support going forward."
Reid, a former Utah lawmaker, has been an outspoken opponent of same-sex marriage and any movement toward the faith's acceptance of these now-legal unions. He supports LDS leaders equating gay marriage with apostasy, an offense triggering disciplinary hearings and possible excommunications, and sees it as a step toward consistency.
"They are treating this," he said, "exactly like they are treating polygamist marriages and the children from polygamist marriages."
Christofferson affirmed this in his video statement, saying there is "a parallel" in the way church leaders view polygamy and same-sex marriage.
The latest LDS handbook also lists polygamy as apostasy, and it places restrictions on the participation of children from such families.
Early Mormons entered plural marriages, but the church abandoned the practice more than a century ago. Participants in polygamy today are branded apostates and are ousted from the faith.
Now, in cases of polygamy and same-sex marriage, people have to be 18 before they can seek approval from the First Presidency to join the LDS Church. To do so, they can no longer live with their parents and must disavow their parents' marriages.
Philip Barlow, professor of Mormon history and culture at Utah State University, said he respects his faith's leaders and believes they didn't intend "a hateful action."
Still, he has reservations.
"I worry for the church that this may cause more hurt than it helps," he said. "The issue has enough potency to further tear at the social fabric of the church over time."
He believes LDS leaders are concerned that if they don't "deepen the boundary" on gay marriage in this way, it will become more accepted among Mormons going forward, a slippery-slope argument bolstered by the nation's rapid acceptance of gay marriage in the past decade.
A Pew Research Center poll released this week shows Mormon acceptance of homosexuality has jumped from 24 percent to 36 percent since eight years ago. And more than a quarter (26 percent) of Latter-day Saints support same-sex marriage.
Barlow recognizes parallels between the faith's handling of gay couples and polygamists, though he said he wouldn't have taken this step.