James was a holy-person (a sanctified-person,
Christian, saint, a child of the only true God) with a Judean/Israeli
background.
He was Jesus’ half-brother because Mary was his mother also, but Joseph
was his father (Matthew 12:46 and 13:55; John 12:5). He was not one of
the twelve whom Jesus had chosen to be his apostles. James had become a
servant of the Lord Jesus Christ (James 1:1) through the appearance to
him of the risen Christ (I Corinthians 15:7); then within a short amount
of time he became a prominent figure in the church in Jerusalem (Acts
12:17, 15:13-21, 21:18, and Galatians 1:19, 2:9 and 12).
James wrote this letter to holy-people who were/are descendants of the 12
tribes of Israel now living in many different areas throughout the world
(Acts 8:1 and 4, 11:19).
He wrote this letter prior to Acts chapter 15, and therefore also before
Paul wrote his letters.