the priests were dealing with superstitious people building civilization from the ashes of the Dark Ages.
Churches had “heads” of saints that moved, too. Statues that bled, more pieces of the cross and Lances of Longinus than you could shake a stick at - all kinds of ‘visual aids’ to impress people with the power of The Word over pagan spells and conjuring.
Notice the Scripture contained in Acts 19 which speaks of casting out demons, not by idols, but by the Name of Jesus Christ. In fact the idols were destroyed.
13 Then certain of the vagabond Jews, exorcists, took upon them to call over them which had evil spirits the name of the Lord Jesus, saying, We adjure you by Jesus whom Paul preacheth.
14 And there were seven sons of one Sceva, a Jew, and chief of the priests, which did so.
15 And the evil spirit answered and said, Jesus I know, and Paul I know; but who are ye?
16 And the man in whom the evil spirit was leaped on them, and overcame them, and prevailed against them, so that they fled out of that house naked and wounded.
17 And this was known to all the Jews and Greeks also dwelling at Ephesus; and fear fell on them all, and the name of the Lord Jesus was magnified.
18 And many that believed came, and confessed, and shewed their deeds.
19 Many of them also which used curious arts brought their books together, and burned them before all men: and they counted the price of them, and found it fifty thousand pieces of silver.
20 So mightily grew the word of God and prevailed.