“The family is central to the Creator’s plan for the eternal destiny of His children. ..In the premortal realm, spirit sons and daughter knew and worshiped God as their Eternal Father and accepted His plan by which His children could obtain a physical body and gain earthly experience to progress toward perfection and ultimately realize his or her divine destiny as an heir of eternal life. The divine plan of happiness enables family relationship to be perpetuated beyond the grave. (“The Family: A Proclamation to the World” LDS Church)
For a Mormon, having strong families is not only a principle to follow but also a key to having happiness in this mortal life. Having children is a primary responsibility and obligation of every husband and wife, so that God’s spirit sons and daughters in the pre-mortal world have the opportunity to progress on earth by acquiring a body. Together, a family can form an important bond that lasts into eternity.
The concept of having eternal families is prevalent in LDS literature. The popular thinking is that most faithful Mormons will have an eternal family. However, LDS teachings specifically state that only Mormons who have reached exaltation will receive an eternal family. They become gods and begin having spirit children of their own.