Biblical monotheism imagines God as a slave master who owns and has total control over humans as his slaves, who are expected to show obedience to him. The theological use of slavery metaphors has a limited value, however, and is deeply problematic from the perspective of real-life slave practices. Ancient authors already supplemented the metaphor of God as a slave master with other images and emphasized God's difference from human slave owners. Ancient and modern experiences of and attitudes toward slavery determined the understanding and applicability of the slavery metaphors. This Element examines the use of slavery metaphors in ancient Judaism and Christianity in the context of the social reality of slavery, modern abolitionism, and historical-critical approaches to the ancient texts.