Some Agreements Among The New Testament Documents About Jesus' Siblings

I've been discussing the perpetual virginity of Mary in some of my recent posts, and one of the issues I've brought up is how often Jesus' brothers are referred to as being together (Matthew 12:46, John 2:12, 7:3, 7:10, Acts 1:14). I think they probably were Jesus' youngest siblings, born well after him (with his sisters and any brothers who didn't survive born earlier), and were still living in the same house after Jesus left. They probably were in their teens to twenties at the time of Jesus' public ministry, with the oldest brother (likely James) having taken over the leadership role Jesus had in the home after Joseph's death. Since Jesus' brothers were still in the same house, they often did things together. The sisters of Jesus are consistently not mentioned in these contexts, even though they are mentioned elsewhere (Matthew 13:56, Mark 6:3). They probably had moved out of the house, whereas Jesus' brothers were still there.

But whatever reason you'd propose for why they're together so often, and whatever view you hold of the perpetual virginity of Mary, the fact remains that the brothers are often referred to as being active together. Later on, the brothers are referred to as being active individually, later in Acts and in Galatians and the letters of James and Jude. The contrast between their acting together earlier and acting individually later can be seen within a single author in the case of Luke. He refers to the brothers' acting together (Luke 8:19, Acts 1:14), but refers to James' acting individually in later passages in Acts. This is another line of evidence for the historicity of the gospels and other parts of the New Testament. The gospels and the opening of Acts all agree that the brothers were active together, with the sisters not being mentioned in those contexts, and the parts of the New Testament discussing later history agree in portraying the brothers as being active in a more individual manner.

One way to appreciate the value of such agreements is to think of how easily the sources could have disagreed. Why agree that Jesus had any brothers? Or more than one? Or that they acted together so often during the timeframe the gospels and Acts 1 cover? Or that they were more individually active later? The sources could easily have been less harmonious and probably would have been if the New Testament were as unhistorical as critics sometimes suggest.