What does that have to do with anything???
Now the birth of Jesus Christ was as follows: After His mother Mary was betrothed to Joseph, before they came together, she was found with child of the Holy Spirit.
Then Joseph, being aroused from sleep, did as the angel of the Lord commanded him and took to him his wife, and did not know her till she had brought forth her firstborn Son.
Define 'her firstborn Son' for me, please.
Someone else has already posted some of the later passages that make it clear that Jesus, according to the flesh, had an unknown number of half-brothers and half-sisters.
I don't know why so many feel compelled to hang on to some strange doctrine, easily disproven, that some ignoramus hatched up centuries ago. They gain nothing by it, and it proves nothing.
2) The Bible was not written in English.
Mark 6:1 ¶And he went out from thence, and came into his own country; and his disciples follow him. 2 And when the sabbath day was come, he began to teach in the synagogue: and many hearing him were astonished, saying, From whence hath this man these things? and what wisdom is this which is given unto him, that even such mighty works are wrought by his hands? 3 Is not this the carpenter, the son of Mary, the brother of James, and Joses, and of Juda, and Simon? and are not his sisters here with us? And they were offended at him. 4 But Jesus said unto them, A prophet is not without honour, but in his own country, and among his own kin, and in his own house.
Context: His own kin, His own country, His own house, they referred to Him as 'the carpenter', come on dude.
Would you like me to post it in koine Greek too?