Chullin 4 - The Path to a Person's Heart is Paved with Food and Drink
Previously we learned that a Jew who habitually eats non-kosher meat can still be trusted with kosher slaughter, since, given the choice, he will expend the minimal effort required, and the kosher slaughter is still significant in his eyes.
Rav Anan said that even a Jew who worships idols - which is considered as an abandonment of the whole Torah - can still do shechitah. We know this because Yehoshaphat, the righteous king of Judah, partook of the feast of idol worshiping Ahab, who thus enticed him to join forces in battle .
But perhaps Ahab slaughtered the animals, but Yehoshaphat did not eat them? - There is no enticement with mere words. Incidentally, although the Torah says "if your brother will entice you (to idol worship)" - that too is done with food and drink. But was not God upset with Satan for enticing Him against Job, without food? - God is different, since He does not eat anyway.
Back to Yehoshaphat, perhaps he only drank but did not eat? - It is not fitting for a king to drink but not eat at a feast.
Art: Paul Gauguin - Portrait Of The Artist With The Idol