WATCH: Mormon Elder Explains Why Children with Gay Parents Aren't Welcome

In a new video interview with Elder D. Todd Christofferson of the Quorum of the Twelve Apostles of The Church of Jesus Christ of Latter-day Saints posted to the site Mormon Newsroom on Friday, the LDS Church further clarified its recent handbook changes in church policy affecting same-sex couples and their children.

The interview comes on the heels of the church's announcement on Thursday that it would deny baptism to children of same-sex couples, and for the first time listed same-sex marriage under the definition of apostasy -- the rejection of church teachings.

"We regard same-sex marriage as a particularly grievous or significant, serious kind of sin that requires Church discipline," Christofferson said in the interview. "We recognize that same-sex marriages are now legal in the United States and some other countries and that people have the right, if they choose, to enter into those, and we understand that. But that is not a right that exists in the Church. That's the clarification."

Christofferson says the changes in church policy barring children with same-sex parents from baptism "originates from a desire to protect children in their innocence and in their minority years" and a "need for a distinction to be made between what may be legal and what may be law of the Church and the law of the Lord" in the wake of the Supreme Court's recent rulings in favor of same-sex marriage in the United States.

The updated policy follows some conciliatory moves by the church, such as supporting an LGBT-inclusive antidiscrimination law in Utah and setting up an outreach website called MormonsAndGays.org. The site, however, repeats the official church teaching that while "same-sex attraction" is not a sin, acting on it is. As for transgender people, the church frowns on gender transition. Christofferson further clarified these recent actions, explaining, "On the one hand, we have worked with others and will continue to do so to protect rights and employment and housing and that sort of thing for all. And on the other hand, there needs to be respect and acknowledgment of the rights of the religious community to set its standards and to live according to them and to teach and abide by its own doctrines, such as regards marriage in this case."

Several people have spoken out about the church's updated policy targeting same-sex couples and their children, including Randall Thacker, president of Affirmation, a group for LGBT Mormons and their allies. Thacker believes these actions will be "incredibly emotionally damaging" to LGBT Mormons, especially young people just coming to terms with their sexuality, and to parents seeking to support LGBT children.

"It is an unfortunate move by the church today," he told The Advocate, explaining neither policy had been codified previously. "It does feel like they're cutting us further off from the community."

Neon Trees lead singer Tyler Glenn, who has worked to mend relationships between the LDS Church and LGBT people since coming out as a proud gay Mormon, took to Twitter to voice his disappointment as well, writing "it's a tough weekend to be a gay Mormon."

"Obviously it's not exactly what we need, but it's changing and that's a positive thing," Glenn said of the LDS Church's stance on LGBT rights in an interview with The Advocatein June. "For me, I feel like I've been able to mend more relationships and cause a lot more change by doing things like speaking to the state senate and working with groups like Equality Utah. And I've noticed over the last year there's been a lot more statements from people in the church, as well as small things within the state government, that are steps in the right direction."

For LGBT Mormon activists like Glenn, the church's new policy is a significant step back from the perceived progress being made, and Christofferson's statements confirm reconciliation between LGBT people and the LDS Church won't occur any time soon.

"We're not going to yield on our efforts to help people find what brings happiness, but we know sin does not," Christofferson says. "And so we're going to stand firm there because we don't want to mislead people. There's no kindness in misdirecting people and leading them into any misunderstanding about what is true, what is right, what is wrong, what leads to Christ and what leads away from Christ."

Watch the full interview below.