President Monson illustrated how temple work and family history work go together,

“In my own family, some of our most sacred and treasured experiences have occurred when we have joined together in the temple to perform sealing ordinances for our deceased
ancestors. . . . The all-important and crowning blessings of membership in the Church are those blessings which we receive in the temples of God.”

President Thomas S. Monson
In Conference Report, Apr. 2011, 87; or Ensign, May 2011, 93