In my last several blogs I gave evidence for Markan priority, that is, Matthew and Luke copying Mark. With this in mind, I now want to turn to discuss the relationship between Matthew and Luke.
Matthew and Luke share a fair amount of material in common that is not found in Mark. This material makes up about 25% of Matthew and 23% of Luke. Refer to the chart in my previous blog to see a visual representation of this.
Why do Matthew and Luke have material in common that is not found in Mark? How do we explain this relationship between Matthew and Luke? Two possible options exist. First, one of the authors copied the other. Scholars refer to this as Matthew and Luke “knowing” each other. Second, they share a common source, which scholars call Q (Q is short for the German word for “source”).
The first option is a simpler theory. Unless there is good reason not to believe the simpler option, we should believe it. In other words, we don’t need to complicate things beyond what is necessary. If Q isn’t necessary, don’t assume it exists.
However, if there is a good reason to doubt that Matthew and Luke knew each other, we need to consider Q. The evidence, which I will show in my next blog, seems to point towards Matthew and Luke not knowing each other. If this is true, then Q is necessary.
