Over the course of history, those works of early Christian literature that survived but that did not become part of the New Testament have been variously grouped by theologians and scholars. Drawing upon, though redefining, an older term used in early Christianity and among Protestants when referring to those books found in the Christian Old Testament although not in the Hebrew Bible, modern scholars began to refer to these works of early Christian literature not included in the New Testament as "apocryphal", by which was meant non-canonical.