Most Bible scholars think Jesus's brother wrote the book.
James didn’t become a believer until after Jesus’ resurrection.
His letter was written to the Jewish Christians, challenging them, very strongly, even bluntly, to live out their faith in their everyday lives.
James 1:1-4
James 1:5-8
James 1:9-12
James 1:13-15
James 1:16-18
James 1:19-21
James 1:22-25
James 1:26-27