Jude 1:1

The first verse of Jude: who was Jude?

1 From Jude, a servant of Yeshua Christ and brother of James.
We find it interesting Jude calls himself a servant of Yeshua Christ,  and brother of James.
I think this is an indication of humility on his part. He shared a mother, Mary with Yeshua (Jesus). He and brothers James, Joseph, and Simon are Jesus' little brothers.
But he mearly calls himself "a servant of Yeshua Christ".
See Matthew13:55
"Isn’t this the carpenter’s son? Isn’t his mother’s name Mary? Aren’t his brothers’ names James, Joseph, Simon, and Judas?"
He did things with Jesus.
See John 2:12
" After this, Yeshua, his mother, brothers, and disciples went to the city of Capernaum and stayed there for a few days."
And like other brothers, he gave advice to his brother Yeshua.
See John 7:3
" So Yeshua’s brothers told him, “Leave this place, and go to Judea so that your disciples can see the things that you’re doing".
At one time however,  he didn't even understand or believe Yeshua was the Christ.
See John 7:5
" 5 Even his brothers didn’t believe in him".
And it appears that Yeshua did as his brothers encouraged.
" 10 But after his brothers had gone to the festival, Yeshua went. He didn’t go publicly but secretly."
In thee end, these brothers of Yeshua believed. And they prayed.
See John 7:10
" 14 The apostles had a single purpose as they devoted themselves to prayer. They were joined by some women, including Mary (the mother of Yeshua), and they were joined by his brothers."
Apearantly Yeshua’s brothers included their wives in the ministry as is indicated in this comment in 1 Corinthians 9:5:
" Don’t we have the right to take our wives along with us like the other apostles, the Lord’s brothers, and Cephas (Peter) do?"
So, we know the author of the book of Jude is one of Jesus,  also known as Yeshua's younger brothers.