The doctrine of the eternity of the marriage covenant and the continuation of the seeds

“The doctrine of the eternity of the marriage covenant and the “continuation of the seeds forever and ever,” is one of the most glorious principles of the Gospel. It is, in fact, the crowning principle which brings the fullness of exaltation to men and women who are willing to accept this eternal, holy and sacred ordinance. It is only in the celestial kingdom that the privilege of marriage and eternal increase will be found. Even in that kingdom there will be servants who are denied this privilege and glory. (D&C Sections 131 and 132:16-17) All who refuse to accept this principle and live in accordance with this covenant cannot be enlarged, but must remain separately and singly through all eternity. They cannot become sons and daughters of God” (We Believe, under Family and Parenthood, 208). Joseph Fielding Smith
spiritualcrusade.com/2006/12/journey-toward-righteousness-several.html