The average age of first marriage for LDS Church members is approximately 23, said Jason Carroll, assistant professor of marriage, family and human development at Brigham Young University.That may not sound old, but the LDS Church teaches that marriage and family are an important part of progression both now and in the afterlife. Young adults in the faith traditionally married as early as 18 during the last half of the 20th century.Nationally, the average age of first marriage jumped from 20 for females and 23 for males in 1960 to 25 and 27 in 2000, respectively, according to the most recent Census data.