I returned late on Saturday night from several days of filming in and near Nauvoo, Illinois. We’re working on the Interpreter Foundation’s forthcoming series of short video documentaries, titled “Becoming Brigham.” The keys of the priesthood were a major focus for this latest round.

By the winter and spring of 1843 and 1844, Joseph Smith’s enemies were forming their plots to kill him and thereby, they hoped, to destroy the Church. Sensing that his time on earth was drawing to an end, the Prophet met frequently with members of the Quorum of the Twelve Apostles not only to instruct them but to bestow upon them the priesthood keys that would be necessary to govern the Church. During an extraordinary meeting in March 1844, Joseph charged the Twelve with leadership of the Church after his death, explaining that he had conferred upon them all of the ordinances, authority, and keys that were necessary for that task.

Until then, only Hyrum Smith (as assistant president of the Church) and Joseph himself possessed the keys; strikingly, although he was a counselor in the First Presidency, Sidney Rigdon did not. “I roll the burden and responsibility of leading this church off from my shoulders on to yours,” Joseph told the Twelve. “Now, round up your shoulders and stand under it like men; for the Lord is going to let me rest awhile.”

Shortly after returning home, I learned of the death of President Russell M. Nelson. And I thought, yet again, of the keys that have resided in the apostleship since that March 1844 meeting. Today, although we mourn the passing of a beloved prophet, there is no leadership crisis or succession struggle, there is no uncertainty. Immediately upon the passing of President Nelson, President Dallin H. Oaks became the senior apostle in the Church of Jesus Christ of Latter-day Saints. And, thus, he is its earthly leader.

I was privileged to have some small personal association with President Nelson, especially in the years just prior to his assumption of the presidency. In my experience with him, he was unfailingly kind and, despite his remarkable secular accomplishments and his lofty ecclesiastical rank, unassuming. As did others, I marveled at his longevity—although, as we all knew, it could not go on forever. He himself quoted the writer of Ecclesiastes in General Conference: “To every thing there is a season, and a time to every purpose under the heaven: A time to be born, and a time to die.” With millions of other Latter-day Saints, I will miss him.

We will miss his continual encouragement for us to be peacemakers, given with gentle good humor: “Anger never persuades,” he taught. “Hostility builds no one. Contention never leads to inspired solutions.

“At this point you may be thinking that this message would really help someone you know. Perhaps you are hoping that it will help him or her to be nicer to you. I hope it will! But I also hope that you will look deeply into your heart to see if there are shards of pride or jealousy that prevent you from becoming a peacemaker.”

We have rejoiced as he has enlarged roles for women as witnesses in the temple and elsewhere in the Church, and built bridges with groups who might previously have viewed us with suspicion or even hostility. We have been thrilled as, at each General Conference, he has announced the construction of numerous temples, bringing the ordinances of salvation and exaltation to Latter-day Saints everywhere—in Bangkok and Lubumbashi, in Mozambique and Mongolia, in Pago Pago and Papua New Guinea. We have loved his clear focus on the Savior, on reminding both Latter-day Saints and others that Jesus Christ is at the absolute center of our faith and, in every sense, its foundation.

Yes, we will definitely miss him. In contemplating President Nelson’s passing, though, it seems appropriate to consider what he himself has had to say about death. I begin with his testimony:

“As a special witness of Jesus Christ,” he declared, “I testify that He lives! I also testify that the veil of death is very thin. I know by experiences too sacred to relate that those who have gone before are not strangers to leaders of this Church. To us and to you, our loved ones may be just as close as the next room—separated only by the doors of death.”

Not only as a Church leader but as an accomplished heart surgeon, President Nelson was well acquainted with death and the threat of death. Moreover, in the latter capacity, he worked often and well to prevent it or, at least, to delay it. But, significantly, he did not regard death as an enemy:

“Scriptures,” he said, “teach that death is essential to happiness: ‘Now behold, it was not expedient that man should be reclaimed from this temporal death, for that would destroy the great plan of happiness.’” (Alma 42:8; italics added; see also 2 Ne. 9:6).

“Life does not begin with birth,” he reminded us, “nor does it end with death. Prior to our birth, we dwelled as spirit children with our Father in Heaven. There we eagerly anticipated the possibility of coming to earth and obtaining a physical body. Knowingly we wanted the risks of mortality, which would allow the exercise of agency and accountability. ‘This life [was to become] a probationary state; a time to prepare to meet God’ (Alma 12:24). But we regarded the returning home as the best part of that long-awaited trip, just as we do now. Before embarking on any journey, we like to have some assurance of a round-trip ticket. Returning from earth to life in our heavenly home requires passage through—and not around—the doors of death. We were born to die, and we die to live (see 2 Cor. 6:9). As seedlings of God, we barely blossom on earth; we fully flower in heaven.”

Drawing upon his medical experience, President Nelson spoke with awe of the remarkable power of human bodies to heal themselves. But, in a striking statement, he also said that God has bestowed upon us a counterbalancing gift:

“It is the blessing of aging, with visible reminders that we are mortal beings destined one day to leave this ‘frail existence.’ Our bodies change every day. As we grow older, our broad chests and narrow waists have a tendency to trade places. We get wrinkles, lose color in our hair—even the hair itself—to remind us that we are mortal children of God, with a ‘manufacturer’s guarantee’ that we shall not be stranded upon the earth forever. “

Death, in President Nelson’s view, is a liberation, a promise of rescue, a ticket home. And, even, seen from a very Latter-day Saint point of view, a kind of comfort for our Heavenly Parents:

“If there were no death . . . the whole reason for our existence would thus be frustrated. . . . After all, he wants us to return to his presence. His highest hopes are for our immortality and eternal life. What loving father or mother does not yearn for the day when a distant daughter or son will return? The longing of the lonesome heart does not ease with the passage of time. It only becomes more intense. Few experiences provide the joy that homecoming brings. The embrace of awaiting parents when their arms envelop a beloved son or daughter is truly sublime. . . . ‘Precious in the sight of the Lord is the death of his saints.’ (Ps 116:15) . . . Reunion, reason, and rounding out of divine intent all reassure us that physical death must be.”

Of course, since our sight is limited by the veil and hindered by our lack of faith, we mortals find it difficult if not altogether impossible to view death as a positive good:

“Even when the elderly or infirm have been afforded merciful relief,” he said, “their loved ones are rarely ready to let go. The only length of life that seems to satisfy the longings of the human heart is life everlasting.

“Irrespective of age, we mourn for those loved and lost. Mourning is one of the deepest expressions of pure love. It is a natural response in complete accord with divine commandment: ‘Thou shalt live together in love, insomuch that thou shalt weep for the loss of them that die’ (D&C 42:45).

“Moreover, we can’t fully appreciate joyful reunions later without tearful separations now. The only way to take sorrow out of death is to take love out of life.”

With such teachings in mind, it is impossible not to think of the joyful reunion that Russell Nelson is now enjoying with his first wife, Dantzel, who passed away suddenly and unexpectedly in 2005; with his two already-deceased daughters, Wendy and Emily; with his parents and others whom he lost over his astoundingly long life.

“Our limited perspective would be enlarged,” he explained, “if we could witness the reunion on the other side of the veil, when doors of death open to those returning home.”

We marveled at his astounding clarity and vigor into exceptional old age. But even Russell M. Nelson, superman though he seemed to be, began to lose his balance and to require assistance when walking, or even a wheelchair. And, in his very last years, he began to lose his eyesight. Very recently, in fact, there have been reports that his vision loss had become quite serious.

Such reports caught my attention: My own father suddenly and completely lost his sight a few years before his death, which came at nearly ninety years of age. We had no family history of such a loss, and it was devastating to all of us—but it was, of course, especially challenging for my father. In his last years, he came to love John Newton’s great hymn “Amazing Grace,” which, I’m delighted to know, is being included in the new official hymnbook of the Church of Jesus Christ of Latter-day Saints: “I once was lost,” Newton wrote, “but now am found, was blind, but now I see.” Dad and President Nelson both see now with perfect clarity, in a realm of everlasting light.

They have been “taken home to that God who gave them life” (Alma 40:11), and, in the Resurrection, their bodies “shall be restored to [their] proper and perfect frame” (Alma 40:23; see also Alma 11:42–45).

So, while we mourn our loss, we should also rejoice in what President Nelson has gained after an exceptionally long life of exceptional service in both medicine and the Church. Now that his turn has come to pass through the doors of death, he can say as did Paul: “The time of my departure is at hand. I have fought a good fight, I have finished my course, I have kept the faith” (2 Tim. 4:6–7).

We will miss President Nelson, and we want to honor him. How can we do that? By centering our lives on Christ, as he urged us to do. By seeking revelation, as he encouraged us to do. By trying to foster peace with and among those around us. And by attending the temple as often as we can, thus participating in the gathering of Israel on the other side of the veil, as well as on this side. Referring to the astonishing surge in temple building that occurred under his leadership, President Nelson remarked that “Building and maintaining temples may not change your life, but spending your time in the temple surely will.“

I have every confidence that President Russell M. Nelson has already heard the words “Well done, thou good and faithful servant.” Still, we mourn him. We will miss him. But, as he himself always assured us, if we follow the covenant path that he so faithfully followed and taught, we too can someday hear those words.