Get the full lesson "Eternal Marriage" from the Teachings of Joseph Fielding Smith at LDS.org.
Note: As the Church has said, the manual has been prepared as the primary source of lesson material. These supplements, from general conference addresses, are meant only as a complement to your study on this lesson’s topic.
Supplement is from Elder Richard G. Scott's talk "Receive the Temple Blessings" from April 1999 general conference:
One of the most beautiful, comforting doctrines of the Lord—one that brings immense peace, happiness, and unbounded joy—is that principle called eternal marriage. This doctrine means that a man and woman who love each other deeply, who have grown together through the trials, joys, sorrows, and happiness of a shared lifetime, can live beyond the veil together forever with their family who earn that blessing. That is not just an immensely satisfying dream; it is a reality. Any husband and wife who have shared the joys of marriage here on earth would want that blessing. But only those who meet the requirements established by the Lord will receive that supernal gift. I bear witness that all those things that have and will bring me the greatest happiness in life have roots in the temple ordinances. Decide now to receive the ordinances of the temple at the appropriate time. Don’t let anything overcome that resolve.
If you are now ready to receive the ordinances of the temple, prepare carefully for that crowning event. Before entering the temple, you will be interviewed by your bishop and stake president for your temple recommend. Be honest and candid with them. That interview is not a test to be passed but an important step to confirm that you have the maturity and spirituality to receive the supernal ordinances and make and keep the edifying covenants offered in the house of the Lord. Personal worthiness is an essential requirement to enjoy the blessings of the temple. Anyone foolish enough to enter the temple unworthily will receive condemnation.
Worthy character is best forged from a life of consistent, correct choices centered in the teachings of the Master. For a moment, I speak to you who are preparing for that sweet period of discovery known as courtship leading to eternal marriage. It can be a wondrously beautiful time of growth and sharing, a time when you should focus your thoughts, actions, and plans on two individuals: the parents of your own future children. Prepare to be a successful parent by being completely worthy in every thought and act during courtship.
Read the full talk, "Receive the Temple Blessings" by Elder Richard G. Scott