"Mary had four other sons, Joseph, James, Jude, and Simon. Because of the virgin birth, Joseph was not the father of Jesus so these were the half brothers of Jesus. The last three mentioned are not to be confused with those who were disciples of Jesus by the same name. Here are some passages where the other sons of Mary by Joseph are mentioned (Matt. 12:46; 13:55; Mark 6:3; John 2:12; 7:3, 5, 10; Acts 1:14; 1 Cor. 9:5; Gal. 1:19).
The Catholic doctrine of the eternal virginity of Mary is not supported by the Scripture. They claim these others were sons of Joseph by a former wife, but there is no biblical foundation for this nor for the perpetual virginity of Mary. The Bible only teaches us that Joseph kept her a virgin until after the birth of Jesus (see Matt. 1:18-25 below)."
