The LDS Church has experienced a landmark year in the use of the religion's "keystone," the Book of Mormon, the president of the church said Saturday.

But President Ezra Taft Benson said members yet have great work to perform in a very short time. He was the opening speaker during the 158th Semiannual Conference of The Church of Jesus Christ of Latter-day Saints."The Book of Mormon is the instrument that God designed to `sweep the Earth as with a flood, to gather out his elect.' The time is long overdue for a massive flooding of the Earth with the Book of Mormon for the many reasons which the Lord has given," he said.

"In this age of the electronic media and the mass distribution of the printed word, God will hold us accountable if we do not now move the Book of Mormon in a monumental way," he stressed. "We have the Book of Mormon, we have the members, we have the missionaries, we have the resources, and the world has the need. THE TIME IS NOW."

Thousands of Mormons converged on Temple Square in Salt Lake City on Saturday to receive counsel from church leaders during opening conference sessions. All LDS general authorities were present except Elder Yoshihiko Kikuchi, mission president in Hawaii, and Elder John H. Vandenberg, who is ill.

People unable to find a seat in the Tabernacle or Assembly Hall took advantage of the beautiful fall weather and stayed on the grounds to listen to the spoken messages, and music by the Mormon Youth Chorus, broadcast outside over loudspeakers.

Thousands more watched in their homes on television or in chapels. All sessions of the conference are broadcast via satellite to more than 2,000 LDS stake centers throughout the United States, Canada and Puerto Rico. Church units in areas of the world where satellite or other transmission is not available will receive videotapes of conference sessions.

The highlight of the opening session was the address of the church's 89-year-old prophet, who reported that the Book of Mormon, "this sacred volume of scripture, has brought more souls to Christ, both within and without the church, than ever before."

President Benson commended many groups and individuals for the progress, but he challenged all members to do more work to flood the Earth with the sacred book.

He challenged church members to participate in the family to family Book of Mormon program; church writers, teachers and leaders to tell more Book of Mormon conversion stories; and people in businesses and other professions to see that copies of the book are in their reception rooms.

"I challenge all of us to prayerfully consider steps that we can personally take to bring this new witness for Christ more fully into our own lives and into a world that so desperately needs it," he said. "I have a vision of the whole church getting nearer to God by abiding by the precepts of the Book of Mormon.

"Indeed, I have a vision of flooding the Earth with the Book of Mormon."

A humble church leader, supported lovingly by his counselors through the session, told an attentive audience that he is in his 90th year.

"I am getting older and less vigorous and am so grateful for your prayers and for the support of my younger brethren," he said. "I thank the Lord for renewing my body from time to time so that I can still help build his kingdom.

"I do not know fully why God has preserved my life to this age, but I do know this: That for the present hour he has revealed to me that absolute need for us to move the Book of Mormon forward now in a marvelous manner. You must help with this burden and with this blessing which he has placed on the whole church, even all the children of Zion."

The religious leader concluded: "Moses never entered the promised land. Joseph Smith never saw Zion redeemed. Some of us may not live long enough to see the day when the Book of Mormon floods the Earth and when the Lord lifts his condemnation. But, God willing, I intend to spend all my remaining days in that glorious effort."

Elder Ashton

Mortals will be measured by the Lord not for their mental capacity or outward appearances _ but by their hearts.

"How do you measure up?" Elder Marvin J. Ashton of the Council of the Twelve asked.

"The measure of our hearts is the measure of our total performance. As used by the Lord, the `heart' of a person describes his effort to better self or others or the conditions he confronts," the church leader said. "Ultimately you and I will be judged not only for our actions, but the desires of our heart."

Elder Ashton suggested four questions that deal with the heart to help church members determine how they measure up.

_ How honest in heart am I? "Honest-hearted persons are individuals without pretense, without hypocrisy," he said. "They are reliable in word and action. They have no hidden agendas to deceive others or to misrepresent facts. In contrast, those with conniving hearts will deceive and misrepresent."

_ Do I have a willing heart? "A willing heart describes one who desires to please the Lord and to serve his cause first," he explained. "He serves the Lord on the Lord's terms, not his own. There are no restrictions to where or how he will serve."

Elder Ashton said he always is pleased to see church members willing to give their time, energy and effort to building the church. "They do so for one primary reason - to serve the Lord with all their heart, might, mind and strength."

_ Do I have an understanding, loving heart? "An understanding, loving heart is the pinnacle of all human emotions," he said. "We come closest to becoming Christlike when we are charitable and understanding to others. One may have many talents and knowledge but never acquire wisdom because he does not learn to be compassionate with his fellow man.

_ "If ye have experienced a change of heart, and if ye have felt to sing the song of redeeming love . . . can ye feel so now?" he said, quoting from the Book of Mormon. Elder Ashton said having a change of heart at one time in our lives is insufficient to give us an understanding heart today.

"Christlike love must be continuous and contemporary," he said.

Elder Faust

Immortality comes to all men, just or unjust, righteous or wicked. But, eternal life, the "greatest of all gifts of God," is obtained only by keeping the Lord's commandments, Elder James E. Faust said Saturday.

Elder Faust, a member of the Council of the Twelve for 10 years, testified that "every person ever born or yet to be born is the beneficiary of both the mediation and the Atonement of the Savior."

"Through the Atonement and those singular events surrounding it, all of the terrible sins of all mankind were individually and collectively taken upon the Lord's shoulders," he explained. "The marvelous result of this great suffering was that he was able to redeem from physical death the believers and the obedient as well as the unbelieving and disobedient."

The general authority said that because of the transcendent act of the Atonement it is possible for every soul to obtain forgiveness of sins, to have them washed away and be forgotten.

"It has been almost 2,000 years since the wondrous occasion when death was conquered. We still do not know how the Savior was able to take upon himself and bear our transgressions, our foolishness, our grief, our sorrows and our hearts," he said. "It was indefinable and unfathomable. It was almost unbearable. The indescribable agony was so great in Gethsemane that `his sweat was as it were great drops of blood falling down to the ground.'

"One cannot help wondering how many of those drops of precious blood each of us may be responsible for."

Elder Faust said that today people still can go to the Garden of Gethsemane, but Jesus can't be found there. Nor is he in the garden tomb, or on the road to Emmaus, nor in Galilee, nor at Nazareth or Bethlehem.

"He must be found in one's heart," he said. "But he left us the great comforter forever and the everlasting power of the priesthood."

Through righteousness, Elder Faust said, "this priesthood power and these supernal gifts of the Atonement and the mediation can operate in our lives."

"Ultimately each of us must come to know these great spiritual truths by following the counsel of Jesus, `If any man will do his will, he shall know of the doctrine, whether it be of God, or whether I speak of myself.' "

Elder Nelson

Elder Russell M. Nelson raised his voice Saturday to join others throughout the world who have spoken against an epidemic of drug addiction.

The physician and member of the Council of the Twelve warned against the abuse of drugs and the recreational or social use of chemical substances "so often begun naively by the ill-informed."

"From an initial experiment thought to be trivial, a vicious cycle may follow. From trial comes a habit. From habit comes dependence. From dependence comes addiction," he said. "Its grasp is so gradual. Enslaving shackles of habit are too small to be sensed until they are too strong to be broken.

"Indeed, drugs are the modern `mess of pottage' for which souls are sold. No families are free from risk."

The church leader said the problem is broader than hard drugs. The magnitude of tobacco's harm is evident, and all of society bears the financial burden of illness "that need not be."

"For the year 1985, the estimated cost of both smoking-related health care and lost productivity amounted to $65 billion. That calculates to an average of $2.17 per pack of cigarettes sold," he said. "Social consequences of smoking far exceed the price paid to purchase cigarettes."

Elder Nelson also expressed concern over the consumption of alcohol - "a factor in nearly half of the nation's murders, suicides and accidental deaths."

"Last year, a tragic milestone was reached,' he said. "More Americans had been killed from alcohol-related motor vehicle deaths than had been killed in all the wars America has ever fought. Drugs such as LSD, marijuana, heroin and cocaine are also endangering people throughout the Earth."

"It is a matter of individual choice and commitment," he said. "Agency must be understood. The importance of the will in crucial choices must be known. Then, steps toward relief can follow."

Bishop Hales

Only if people have an eternal plan as a goal in their lives will they make correct choices at the crossroads of life, Presiding Bishop Robert D. Hales said Saturday morning.

Bishop Hales, whose address was full of poignant stories that aroused laughter and tears, emphasized that "to attain eternal life is why we came to Earth. Eternal life is our goal."

However, he cautioned that people cannot make the right eternal choices based solely on "pure intellectual deduction and factual analysis from our own understanding: Prayer and study must be used together to build knowledge and wisdom."

Study and prayer also should include seeking wise counsel, plus a willingness by a person to take responsibility for his own actions.

"A good check and balance in decision- making is to look at our motive for making our decision," Bishop Hales said. "Beware of fear and greed. Be aware of your true motives. We make poor and irrational decisions if our decision is motivated by greediness _ greed for monetary gain, greed that results in a conflict of interest, desire for power, titles and recognition of men."

Likewise, he said, people make poor and irrational decisions if their decisions are motivated by fear.

"When we stand at the crossroads of life and must make a decision whether to go to the great and spacious building of the world's ways or the straight and narrow path that leads to eternal life, we cannot travel both roads _ although sometimes we try," Bishop Hales said. "It is difficult to come back, but we can; and our greatest satisfaction will more than likely come from taking the lonelier road which is less traveled."