You cannot partake of the table of the Lord and of the table of demons.
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." Many martyrs died for not adoring "the Beast" refusing even to simulate such worship. Idolatry rejects the unique Lordship of God; it is therefore incompatible with communion with God.
-- CCC 2113