Sister See also Brethren, Brother; Man, Men; Woman, Women As children of our Heavenly Father, all men and women are spiritually brothers and sisters. In the Church, female members and friends of the Church are often addressed as sisters. Those who do the will of my Father, the same is my brother and sister, Matt. 12:50 (Mark 3:35). Laws governing confession of sins between brothers and sisters in the Church are set forth, D&C 42:88–93.