According to a prevailing theory of biblical scholarship called the documentary hypothesis, the Pentateuch (the first five books of the Bible) was written at different times by several different authors and was later combined into a single narrative. To identify the sources, Bible scholars use the letters J, E, P and D for Yahwist (or Jehovist), Elohist, Priestly and Deuteronomistic, respectively. (See “The Documentary Hypothesis in Trouble,” BR 01:04, and “A New Challenge to the Documentary Hypothesis,” BR 01:04.)