Inside One of the Holiest Rooms in Mormon Temple

The Celestial Room in the Kansas City Temple of The Church of Jesus Christ of Latter-day Saints is shown in this 2012 photo. (Intellectual Reserve, Inc.)

It's a room few get to see, with high ceilings, comfortable furnishings and an ethereal brightness that's meant to evoke images of heaven.

Called the Celestial Room, it's one of the most sacred rooms of a Mormon temple.

The purpose of the room is "to remind us that we're on our way back to God. We're on our way back to Heaven. That's our objective," Elder William R. Walker, a senior leader within the Church of Jesus Christ of Latter-day Saints - also known as the Mormon Church - told Barbara Walters in a recent interview.

And not just any Mormon can enter a Celestial Room, only Mormons in good standing are allowed to enter.

This Friday, on a special two-hour "20/20," Barbara Walters meets with religious leaders from different faiths around the world to get a range of perspectives on heaven and the afterlife.

For Mormons, heaven consists of three degrees, with the most dutiful residing in the top level.

"One of the things that distinguishes our belief and our faith is we don't think you just say, 'I believe in Jesus,' and you go straight to heaven," Walker said. "We think that our lives will be evaluated based on how we lived - we lived with a love for others, if we contribute to society, if we keep the Commandments of God."

Watch the full story Friday on a special two-hour "20/20," starting at 9 p.m. ET.