Robert H. Pfeiffer's posthumous "Religion in the Old Testament" reveals a scholar deeply wedded to 19th-century Wellhausen School biblical criticism, even as the field evolved dramatically around him. Through comprehensive textual analysis of Pfeiffer's treatment of ancient Israelite religious development and biblical source interpretation, this review exposes how his work remained anchored in outdated theoretical frameworks despite his extensive knowledge of contemporary scholarship, evidenced by citations of over 350 field-relevant works. Pfeiffer's steadfast commitment to the documentary theory's evolutionary model portrays Israel's religious journey as a linear progression from primitive animism through polytheistic and henotheistic phases, culminating in monotheism with Deutero-Isaiah in the sixth century. His selective textual interpretation methodology notably disregards contradictory archaeological evidence from Mari and Nuzi tablets, exemplifying how adherence to 19th-century Hegelian philosophical assumptions rendered his work anachronistic against modern Near Eastern archaeological discoveries and contemporary biblical scholarship.