The Lord has instructed his people to build temples since ancient times. The Bible speaks of the Tabernacle of the Israelites in the wilderness, Solomon's Temple, and the Temple of Herod.
In addition to regular Sunday worship, Latter-day Saints also follow the biblical practice of worshipping in temples. The Church operates 168 dedicated temples throughout the world (as of 2020). By comparison, there are over 17,000 chapels for Sunday worship services. Latter-day Saints believe that temples are the most sacred places on earth—sanctuaries from the distractions and commotion of life. A temple is a place where the most cherished of human relationships are made eternal. Accordingly, it is only fitting and appropriate that the lives of those who worship there reflect that sacredness. Thus, unlike regular Sunday worship, to which all are invited, temple worship is set aside for Latter-day Saints who observe the basic principles of the faith.
Because temples are architecturally beautiful and often prominently placed, many inquire about visiting them and are disappointed to find out that only Church members in good standing may enter. It is noteworthy, however, that the general public is invited to participate in educational tours of the interior of temples after their construction is complete but before they are officially dedicated and opened.
To account for the diversity of religious experience, many religions have traditionally made space in their worship practices for the public and the private, the common and the sacred, the routine and the exceptional, the wide and the narrow. These sanctuaries serve a much different purpose than regular worship services intended for larger audiences. It is no different with the Latter-day Saints. 
Former prophet and president of the Church, Gordon B. Hinckley, said,
ordinances are performed, the temple is a place of peace and revelation. It is a place where spiritual guidance can be received for crucial decisions or concerns.
These sacred buildings were constructed even during those dark years when the Latter-day Saints were relentlessly driven and persecuted. They have been built and maintained in times of poverty and prosperity. They come from the vital faith of an ever-growing number who bear witness of a living God, of the resurrected Lord, of prophets and divine revelation, and of the peace and assurance of eternal blessings to be found only in the house of the Lord.
The work that goes on in these buildings sets forth God's eternal purposes with reference to man—God's children and creation. For the most part, temple work is concerned with the family, with each of us as members of God's eternal family and with each of us as members of earthly families. It is concerned with the sanctity and eternal nature of the marriage covenant and family relationships.
It affirms that each man and woman born into the world is a child of God, endowed with something of His divine nature. The repetition of these basic and fundamental teachings has a salutary effect upon those who receive them, for as the doctrine is enunciated in language both beautiful and impressive, the participant comes to realize that since every man and woman is a child of Heavenly Father, then each is a member of a divine family; hence, every person is his brother or sister.
Again, from President Hinckley:
I wish to say to everyone here, come to the temple. Live worthy to come to the temple. Live the commandments of God so that you may come to the temple. Do those things which will make you eligible to serve in the house of the Lord. It has been built for you, my brothers and sisters, that you might have the opportunity of coming here and receiving the wonderful blessings that can be had nowhere else in all the world, except in other temples, where you may be sealed together as husband and wife, where your children may be sealed to you, where you may work in behalf of your forebears, who have gone beyond. That great and marvelous and wonderfully unselfish work occurs in the house of the Lord. Come to the temple .
See Inside Mormon Temples, Temple endowment, Baptism for the Dead, Mormon Temples, Mormon garments, Celestial marriage
- Church News, "Inside Church Headquarters: The location, design and construction of temples"
- New Interactive Map of Worldwide LDS Temples
- "Spiritual Treasures by President Russell M. Nelson
- Gospel Topics: Temples
- The Purpose of Temples By President David O. McKay
- "The Temple in Time and Eternity" by Donald W. Parry and Stephen D. Ricks