Leviticus 20:27 prescribes death by stoning for mediums and those with 'familiar spirits' — God executing people for practicing psychic phenomena.

Leviticus 20 is theocratic civil-judicial legislation for the covenant nation of Israel, structured (like the whole Sinai law) on the pattern of an ancient Near Eastern suzerain-vassal treaty between Yahweh and Israel (Meredith Kline, *Treaty of the Great King*). Within that framework, mediumship and necromancy were not treated as neutral private practices but as covenant treason: attempts to access power and knowledge through a rival spiritual allegiance, in direct violation of the treaty's first and defining clause (Exod 20:3, 'no other gods before me'). Deuteronomy 18:9-14 groups mediums and necromancers together with child sacrifice as 'detestable practices of the nations' that Israel is displacing — indicating the concern is covenantal exclusivity and the protection of Israel's unique redemptive-historical vocation, not merely policing fortune-telling as a nuisance crime. Ancient Israelite civil law regularly imposed capital sanctions on what modern secular law would not criminalize at all (e.g., sabbath violation, certain sexual offenses) because it was operating as the judicial code of a covenant nation, not a generically applicable universal ethic — exactly as many historic human legal codes have reserved their harshest penalties for treason against the sovereign, even when the treasonous act (passing information, symbolic allegiance to a rival power) caused no direct physical harm. Honesty requires conceding real difficulty here rather than dissolving it: this remains a severe, uncomfortable penalty by any modern standard, and the text gives no indication of proportional gradation for degrees of the offense. The Christian answer is not that this penalty transfers into contemporary or even New Testament ethics. Aquinas's threefold division of the Mosaic law into moral, ceremonial, and judicial precepts (ST I-II q.99, aa.3-4) holds that the judicial precepts 'did not bind for ever, but were annulled by the coming of Christ' — they governed Israel's own civil polity for a bounded historical period, not universal moral order. The apostolic church, operating under Roman civil law and explicitly stripped of theocratic magisterial power, never attempted to execute mediums; Acts 19:19 depicts former practitioners of magic converting and burning their own scrolls, with no civil penalty invoked at all.

The severity of the sanction is in service of a specific, historically bounded purpose: preserving the unique monotheistic, covenantal integrity of the one nation through which the Messianic promise-line (Gen 12:1-3) was to be preserved amid a Canaanite religious environment saturated with divination, necromancy, and child sacrifice. A jealous exclusivity clause in a covenant is not petty possessiveness but the marital-covenant logic Scripture itself invokes (Exod 20:5, Hosea 2) — analogous to the justified, non-arbitrary exclusivity built into any covenantal or marital bond.