About Jesus Bretheren
John, Chapter 7
1 After these things Jesus walked in Galilee: for he would not walk in Jewry, because the Jews sought to kill him.
2 Now the Jew's feast of tabernacles was at hand.
3 His brethren therefore said unto him, Depart hence, and go into Judaea, that thy disciples also may see the works that thou doest.
4 For there is no man that doeth any thing in secret, and he himself seeketh to be known openly. If thou do these things, shew thyself to the world.
5
For neither did his brethren believe in him.
6 Then Jesus said unto them, My time is not yet come: but your time is alway ready.
7 The world cannot hate you; but me it hateth, because I testify of it, that the works thereof are evil.
8 Go ye up unto this feast: I go not up yet unto this feast: for my time is not yet full come.
9 When he had said these words unto them, he abode still in Galilee.
10 But when his brethren were gone up, then went he also up unto the feast, not openly, but as it were in secret.
More about James (and Jude)
James, the brother of Jude and the half brother of Jesus, was the leader of the Jerusalem church. When Jude identified himself as the "brother of James", he immediately acquired a lot of credibility, because James was a well-known man and an outstanding leader. That would help people listen to what he had to say. I think it is an interesting footnote that when James wrote his epistle, he humbly said that he was "a servant of God and of the Lord Jesus Christ..." (v. 1). He too, was the half brother of Jesus, but he didn't draw any attention to that fact. Like Jude, he recognized that the family relationship didn't matter anymore.
The brothers of Jesus didn't consider themselves servants of Jesus until they had experienced a major change in their lives. Apparently, the brothers had grown up resenting Jesus. John 7:5 says, "For neither did His brethren believe in Him." Jesus' brothers mocked Him in verses 2-4, not really believing that He was the Messiah. Yet, their lives were transformed at some point, for both James and Jude changed from those who resented Jesus to those who were willing to be His servants. Somewhere along the line, they were converted. I believe it probably happened after the resurrection. Jesus appeared to James after He rose from the dead according to 1 Corinthians 15. That appearance must have finally convinced the two brothers, who then saw themselves as servants of Jesus Christ."
BIBLE STUDY MANUALS: MARY, DID SHE HAVE CHILDREN AFTER GIVING BIRTH TO OUR LORD?
Why did Jesus entrust Mary to be cared for by John?
John was, as it says in this context, "the disciple whom Jesus loved" (cf. also Jn.13:23; 20:2; 21:7; 21:20). Since our Lord's judgment was perfect, this means that John certainly had a lot going for him relative to the other disciples. And the qualities which attracted our Lord to John must have been primarily spiritual. We certainly see His great humility and responsiveness to the leading of the Spirit in his gospel and his epistles. And John, of course, lived longer than any of the rest, penning the final book of the Bible, the book of Revelation, apparently just before his death in circa 64-68 A.D. For all these reasons, John seems to have been the best choice and indeed the perfect choice to look after Mary.
Why did Jesus choose John over James to take care of His mother Mary?