Luke, a Plagiarist?

For many years scholars and laymen have been perplexed by certain seeming discrepancies that crop up when various incidents in Jesus' ministry are compared. Not only that, but in some instances it is evident that the Gospel writers copied from one other or from a common source. Thus, for instance, an estimated 91 percent of the Gospel according to Mark is reproduced by Matthew and Luke.

Must a Bible writer be original, and must his writings agree in every detail with every other Bible write...