Ten years ago on the blog when I was discussing the Proto-Gospel of James (the current subthread within a thread), I received an intriguing question about this issue, addressed in the previous post, about the brothers of Jesus and how “mythicists” — those who claim there never was a historical Jesus whatsoever but that he was completely made up (a “myth”) — dealt with them. Here’s the question and my response.
Since you’ve brought up the subject of Jesus’ family perhaps it won’t be too far off the subject to ask this question.
Mythicists are forced by their arguments to deal with Paul’s encounter with Peter and James in Galatians 1:18–20. They claim that when Paul refers to James as “The Lord’s brother” he does not mean that James is Jesus’ biological brother (which of course would mean that Jesus actually lived) but that he was using the word “brother” in the sense that all the disciples were “brothers” i.e., metaphorically.
What about this? Is the word translated as “brother” in English that ambiguous in the original Greek? Can it be other than a biological relationship? Elsewhere I believe Paul uses the word “brothers” to describe fellow believers. Does he use the same Greek word?