The author of this letter must have been well known in the church because there is no more specific information in this letter as to who he is other than what we find in James 1:1: James, a servant of God and of the Lord Jesus Christ, to the twelve tribes which are scattered abroad, greeting.
Thus, we can narrow down the options of his identity pretty quickly. Four people in the New Testament are named James: there are two of the twelve disciples (Mark 3:17-18); there is the father of Judas (another of the twelve but not Judas Iscariot, Luke 6:16, NKJV) and one of Jesus’ brothers (Mark 6:3). Of these four, only the brother of Jesus lived long enough and was prominent enough in the church to have penned such a letter. Thus, we believe that it was James, the brother of Jesus, who authored this New Testament book.
As a carpenter’s son (Matt. 13:55), James would have had more educational opportunities than would a common peasant. His letter is among the best examples of literary Greek in the New Testament. Its rich vocabulary, rhetorical flair, and command of the Old Testament are surpassed only by Hebrews. Because his name appears first in the list of Jesus’ brothers, James was probably the oldest son. However, the fact that Jesus entrusted the care of His mother to John, the beloved disciple (John 19:26-27), suggests that His brothers were not Mary’s own children but the sons of Joseph by a previous marriage.
In the context of Jesus’ ministry read this verse: When his family heard about this, they went to take charge of him, for they said, He is out of his mind (Mark 3:21, NIV; see also John 7:2-5). What do these texts tell us about how Jesus had been perceived by His own family? What lessons can we draw from them for ourselves, if indeed at times we find ourselves misunderstood by those whom we love?
It was a false conception of the Messiah’s work, and a lack of faith in the divine character of Jesus, that had led His brothers to urge Him to present Himself publicly to the people at the Feast of Tabernacles.-Ellen G. White, The Desire of Ages, p. 485, 486.