Those who attended or watched the 159th General Conference of The Church of Jesus Christ of Latter-day Saints on Saturday saw some important history being made.

It's the kind of history that reflects not only the growth of the church's membership throughout the world, but also the flexibility of the church in meeting this challenge.Likewise, it's also the kind of history that indicates the width and depth of the outstanding pool of talent that can be mustered to deal with present growth and prepare for even more of it.

We're referring, of course, to the organization of a new Second Quorum of the Seventy for those Seventies serving under a five-year call and to the appointment of 12 new general authorities. For the present, these changes will leave the First Quorum of the Seventy with 35 members plus the seven presidents and the Second Quorum with an initial membership of 36.

Among the 12 new general authorities are those with impressive backgrounds not only in church service but also in higher education, law, business, medicine and communications.

They are men who are not only extremely capable, but also humble and unassuming. That's because they can be characterized as teachable, as one must be when shouldering the demanding responsibilities of helping to lead a world-wide organization. And because such leaders also serve as personal examples of spirituality and dedication.

The challenges facing the new general authorities can only partly be measured by the growth of the LDS Church to 6,720,000 members at the end of 1988, an increase of 280,000 during the past year. Since the gospel of Christ is intended for all mankind, this part of the challenge is bound to keep getting bigger and more complex.

The challenge is not just to keep accumulating more numbers but to keep growing and progressing in terms of righteousness and character development. Likewise, as the church grows and spreads, a major part of its challenge will be to maintain and increase the unity that Christ demands of all his disciples.

Such unity can come only from full obedience to all the truths of salvation. Nor is full unity possible without an abundance of toleration and love. Love, in turn, always manifests itself in service to others - like the generous service being rendered by the new general authorities called on Saturday and the many spiritual leaders they joined at the Temple Square conference.

Finally, bear in mind that the historic changes outlined Saturday at general conference represent not a plateau to rest on but a new foundation from which not just the church but its individual members are to keep building.