Access to Temple Ordinances, Knowledge of the Mysteries of the Kingdom, and the Ability to See God and Stand in His Presence

Doctrine and Covenants 84:19–22

19 And this greater priesthood administereth the gospel and holdeth the key of the mysteries of the kingdom, even the key of the knowledge of God.
20 Therefore, in the ordinances thereof, the power of godliness is manifest.
21 And without the ordinances thereof, and the authority of the priesthood, the power of godliness is not manifest unto men in the flesh;
22 For without this no man can see the face of God, even the Father, and live.

President Joseph Fielding Smith said:

“This matter of holding the priesthood is not a light or a small thing. We are dealing with the Lord’s power and authority, which He has given to us by the opening of the heavens in this day so that every blessing might again be available to us, as they were when man was first placed upon the earth.”

(“Blessings of the Priesthood,” Ensign, Dec. 1971, 98.)