(by Elder Dallin H. Oaks October 2008 General Conference)
The ordinance of the sacrament makes the sacrament meeting the most sacred and important meeting in the Church.
We live in the perilous times prophesied by the Apostle Paul (see 2 Timothy 3:1). Those who try to walk the straight and narrow path see inviting detours on every hand. We can be distracted, degraded, downhearted, or depressed. How can we have the Spirit of the Lord to guide our choices and keep us on the path?
In modern revelation the Lord gave the answer in this commandment:
“And that thou mayest more fully keep thyself unspotted from the world, thou shalt go to the house of prayer and offer up thy sacraments upon my holy day;
“For verily this is a day appointed unto you to rest from your labors, and to pay thy devotions unto the Most High” (D&C 59:9–10).
(for remainder of talk please see https://www.lds.org/general-conference/2008/10/sacrament-meeting-and-the-sacrament?lang=eng)