Studying Foreign Theologies
"Do not turn to the idols"—Leviticus 19:4.
We are forbidden to study or even dabble in idolatrous teachings. Such activity can lead an individual without sufficient intelligence or knowledge to stray after these false teachings. Furthermore, it is forbidden to even gaze at an idol or idolatrous icon.
Straying After Incorrect Beliefs and Illicit Pleasures
"And that you stray not after your heart and eyes"—Numbers 15:39.
We are to keep our eyes and hearts in check, never succumbing to the allure of beliefs and urges antithetical to Torah values. We are obligated to maintain control over our thoughts—not to allow our hearts to lead us to heretical beliefs, nor our eyes to lead us to indulge in thoughts about illicit pleasures.
Cursing G‑d
"Do not curse G‑d"—Exodus 22:27.
We are forbidden to curse G‑d. This prohibition applies whether using one of G‑d's holy names, or even if referring to Him through other monikers.
Unique Modes of Idol Worship
"Do not worship them"—Exodus 20:5.
We are forbidden to worship an idol employing any practice unique to that idol. For example, in ancient times there was an idol called Markulis. Its worship called for casting a rock in its direction. Throwing a rock at Markulis would be a violation of this prohibition—while throwing a rock at any other idol would not.
(This is in addition to specific modes of idol worship that are forbidden whether or not they are part of the protocol prescribed for that deity. See Negative Mitzvah 5 for more on this topic.)
Idol Worship
"Do not bow down to them"—Exodus 20:5.
It is forbidden to worship any deity other than the One G‑d in any of the following manners: 1) Bowing. 2) Slaughtering a sacrifice. 3) Pouring a libation. 4) Burning a sacrifice on an altar. These prohibitions apply even if these acts are not the accepted way of worshipping that particular deity.
Aside from these four actions, it is also forbidden to verbally declare belief in a deity other than G‑d.
Manufacturing Idols
"Do not make any carved idols for yourself"—Exodus 20:4.
It is forbidden to make, or to commission the making of, a graven image for the sake of worshipping it.
Making Idols for Others
"Do not make gods out of metal for yourselves"—Leviticus 19:4.
It is forbidden to create a graven image for another, even for a non-Jew.
Ornamental Statuettes
"Do not make with Me gods of silver or gold; you shall not make for yourselves"—Exodus 20:20.
We are not allowed to create the graven image of a human being, even if only for ornamental or decorative purposes.
Inciting a Group to Idol Worship
"Neither let [idolatry] be heard from your mouth"—Exodus 23:13.
It is forbidden to incite a populace to idolatry.
City of Idol Worshipers
"And burn the city with fire"—Deuteronomy 13:17.
If the citizenry of a city has been influenced to worship idols, we are commanded to destroy the city, kill its inhabitants, and burn all its property.
Rebuilding the "Apostate City"
"It shall remain a ruin forever; it shall never be rebuilt"—Deuteronomy 13:17.
A city that has been destroyed because its citizens were persuaded to worship idols (see Positive Commandment 186) may never be rebuilt.
Benefiting from the "Apostate City"
"Let nothing that has been condemned to destruction remain in your hand"—Deuteronomy 13:18.
Everything contained within the "Apostate City" (see Positive Commandment 186) must be burned. It is forbidden to use, or derive any benefit from, any object from such a city.