Complex sentence: He returned to Minneapolis in 1958 and served until his death as board chairman of Lutheran Brotherhood, a fraternal insurance society he had co-founded in 1917 he also founded the Aid Association for Lutherans, which consolidated in the 1990s to become Thrivent Financial for Lutherans.
Split into simpler sentences: He returned to Minneapolis in 1958 and served until his death as board chairman of Lutheran Brotherhood, a fraternal insurance society he had co-founded in 1917. He also founded the Aid Association for Lutherans, which consolidated in the 1990s to become Thrivent Financial for Lutherans.