Upvote:4
Most non-Catholic denominations do not believe in the perpetual virginity of Mary, and fully accept the idea of Jesus having biological half-brothers. (Only He has God for a Father.)
From a perspective of Sola Scriptura, there's no support for the idea that Mary remained a virgin through life, and there is Biblical evidence that Jesus had brothers.
*Please do not take the following quote as me endorsing a view that rejects or accepts the perpetual virginity of Mary. I'm including it to support the paragraph above.
From http://www.gotquestions.org/perpetual-virginity-Mary.html
So, what does the Bible say about the perpetual virginity of Mary? Using the New American Bible, which is a Catholic translation, we can see that the perpetual virginity of Mary is not taught in the Bible. Matthew 1:25 NAB tells us, "He had no relations with her until she bore a son, and he named him Jesus." He, Joseph, did not have sexual relations with her, Mary, UNTIL after she bore a son, Jesus." The meaning of this Scripture is abundantly clear. Joseph and Mary did not have sexual relations until after Jesus was born. Matthew 13:55-56 NAB declares, "Is He not the carpenter's son? Is not his mother named Mary and his brothers James, Joseph, Simon, and Judas? Are not His sisters all with us?" Catholics claim, correctly, that the Greek terms for "brothers" and "sisters" in these verses could also refer to male and female relatives, not necessarily literal brothers and sisters. However, the intended meaning is clear, they thought Jesus to be Joseph's son, the son of Mary, and the brother of James, Joseph, Simon, and Judas, and the brother of the unnamed and unnumbered sisters. Father, mother, brother, sister. It is straining the meaning of the text to interpret “brothers” and “sisters” as "cousins" or "relatives" with the mentioning of Jesus' mother and father.
However, there are Protestant denominations that still accept the doctrine of the Perpetual Virginity of Mary.
The view on whether Jesus had biological brothers is, therefore, varied, and the view hinges on whether or not you accept that doctrine.
For more on Protestant views on the doctrine of perpetual virginity, see What do Protestants say was the source for the doctrine of the perpetual virginity of Mary?