After the miraculous conception of Jesus, Mary, and Joseph had other children as well. The gospels report that Jesus had at least four brothers and some sisters: “Isn’t this the carpenter’s son? Isn’t his mother’s name Mary, and aren’t his brothers James, Joseph, Simon and Judas? Aren’t all his sisters with us?” (Matthew 13:55, also Mark 6:3). And the gospels also record, that while Jesus was alive, his brothers did not believe in Him: “For even his own brothers did not believe in him” (John 7:5). The Scriptures do not sugarcoat this. The lack of belief by James and the other brothers is corroborated by the absolute silence about them in the gospels. None of the accounts of Jesus’ ministry mentions them in any role.
However, after the resurrection, in the earliest years of Christianity, James, the brother of Jesus, became a significant player in the movement. In Galatians 1:19, Paul explicitly identified him as one of the only two individuals he met with during his 37 AD trip to Jerusalem: “I saw none of the other apostles—only James, the Lord’s brother.” So, there cannot be any doubt that James, Jesus’ brother, had within four years of the resurrection not only converted to Christianity; he had become a recognized leader in the early church.
Later on Paul also gives an important clue as to why James became a Christian. In the early resurrection creed in 1 Corinthians 15:3-8, Paul writes that Jesus also appeared to James: “Then he appeared to James”(1 Corinthians 15:7). One can argue which James this is (lack of surnames in Bible times can occasionally be quite confusing). However, the context makes it clear, that this is not James the son of Zebedee (the brother of John) or the other apostle James, James the son of Alphaeus (as they are mentioned as part of the apostle group before). Therefore this must be James, the Lord’s brother.
Subsequently, in Acts 12:17 and 15:13 this same James is recognized after the resurrection as a leader of the church in Jerusalem. And he also wrote the New Testament book by that name.
An important, non-Biblical confirmation comes to us from Josephus: “Ananus…assembled the Sanhedrin of judges, and brought before them the brother of Jesus, who was called Christ, whose name was James, and some others, …, he delivered them to be stoned.” This passage does not only confirm that James was the brother of Jesus, it also mentions that he was martyred for his faith by stoning (around 57 AD).
All in all, it is a well-founded conclusion that James, the brother of Jesus – like Paul – made a remarkable conversion from a non-believer during the lifetime of Jesus to a leader in the earliest years of the Christian movement and was ultimately stoned for his faith. Although the personal appearance of the risen Jesus to His brother James is reported only once in the New Testament, this reported encounter is part of the powerful early resurrection creed dated back to only a few years after the resurrection. And one can wonder: What could have ever happened to James that could have converted him to a believer apart from the appearance of the resurrected Christ? James knew Jesus while He was alive and certainly knew about His teachings and even Jesus’ miracles. None of this, however, convinced him, so what could the apostles have said to convince this man?
Logically, only a personal encounter with the resurrected Jesus, as mentioned by Paul, would explain his 180-degree change in beliefs and actions. Therefore James' conversion is another confirmation of the historical reliability of the resurrection of Jesus of Nazareth.