Well, when many who practiced magic came to believe on the Lord Jesus, they brought their books together and burned them all, before men. All of these practices and more, were and still are carried on. All done in connection with 'Familiar Spirit' or demons. ALL who forsake God and seek help from these demons are to be destroyed. Read Revelation 13.
Devils can work miracles, insomuch that even the very elect can be deceived.
Deception is the bottom line with satan. He comes to deceive, steal, destroy AND kill. Because of hatred. Satan hates God so much, that he will do anything to pull people away from Him. Christianity, Religion etc. is not the way to heaven.