Deuteronomy Chapter 18: 9-14
9 "When you come into the land which the Lord your God is giving you, you shall not learn to follow the abominations of those nations. 10 There shall not be found among you anyone who makes his son or his daughter pass through the fire, or one who practices witchcraft, or a soothsayer, or one who interprets omens, or a sorcerer, 11 or one who conjures spells, or a medium, or a spiritist, or one who calls up the dead.
12 For all who do these things are an abomination to the Lord, and because of these abominations the Lord your God drives them out from before you. 13 You shall be blameless before the Lord your God. 14 For these nations which you will dispossess listened to soothsayers and diviners; but as for you, the Lord your God has not appointed such for you.
III. "YOU SHALL HAVE NO OTHER GODS BEFORE ME"
2110 The first commandment forbids honoring gods other than the one Lord who has revealed himself to his people. It proscribes superstition and irreligion. Superstition in some sense represents a perverse excess of religion; irreligion is the vice contrary by defect to the virtue of religion.
Superstition
2111 Superstition is the deviation of religious feeling and of the practices this feeling imposes. It can even affect the worship we offer the true God, e.g., when one attributes an importance in some way magical to certain practices otherwise lawful or necessary. To attribute the efficacy of prayers or of sacramental signs to their mere external performance, apart from the interior dispositions that they demand, is to fall into superstition.41
Idolatry
2112 The first commandment condemns polytheism. It requires man neither to believe in, nor to venerate, other divinities than the one true God. Scripture constantly recalls this rejection of "idols, [of] silver and gold, the work of men's hands. They have mouths, but do not speak; eyes, but do not see." These empty idols make their worshippers empty: "Those who make them are like them; so are all who trust in them."42 God, however, is the "living God"43 who gives life and intervenes in history.
2113 Idolatry not only refers to false pagan worship. It remains a constant temptation to faith. Idolatry consists in divinizing what is not God. Man commits idolatry whenever he honors and reveres a creature in place of God, whether this be gods or demons (for example, satanism), power, pleasure, race, ancestors, the state, money, etc. Jesus says, "You cannot serve God and mammon."44 Many martyrs died for not adoring "the Beast"45 refusing even to simulate such worship. Idolatry rejects the unique Lordship of God; it is therefore incompatible with communion with God.46
2114 Human life finds its unity in the adoration of the one God. The commandment to worship the Lord alone integrates man and saves him from an endless disintegration. Idolatry is a perversion of man's innate religious sense. An idolater is someone who "transfers his indestructible notion of God to anything other than God."47
Divination and magic
2115 God can reveal the future to his prophets or to other saints. Still, a sound Christian attitude consists in putting oneself confidently into the hands of Providence for whatever concerns the future, and giving up all unhealthy curiosity about it. Improvidence, however, can constitute a lack of responsibility.
2116 All forms of divination are to be rejected: recourse to Satan or demons, conjuring up the dead or other practices falsely supposed to "unveil" the future.48 Consulting horoscopes, astrology, palm reading, interpretation of omens and lots, the phenomena of clairvoyance, and recourse to mediums all conceal a desire for power over time, history, and, in the last analysis, other human beings, as well as a wish to conciliate hidden powers. They contradict the honor, respect, and loving fear that we owe to God alone.
2117 All practices of magic or sorcery, by which one attempts to tame occult powers, so as to place them at one's service and have a supernatural power over others - even if this were for the sake of restoring their health - are gravely contrary to the virtue of religion. These practices are even more to be condemned when accompanied by the intention of harming someone, or when they have recourse to the intervention of demons. Wearing charms is also reprehensible. Spiritism often implies divination or magical practices; the Church for her part warns the faithful against it. Recourse to so-called traditional cures does not justify either the invocation of evil powers or the exploitation of another's credulity.