Allāh says (what can be translated as):

Sulayman did not disbelieve, but the Shayatīn (devils) disbelieved, teaching men magic.
[Sūrah al-Baqarah, 2:102]

Magic is a severe form of disbelief, and this severity is shown by the punishment that the magician is faced with. The magician faces capital punishment, even if he/she repents, he/she may still face capital punishment (in the Islamic legal system, the courts), according to a number of scholars.

Heedlessness has overcome the Muslims today, such that you will find in some of the Muslim homes, books called Harry Potter, in these books you will find pure disbelief in Islām. After the children have read lots of books containing severe disbelief, a parent may say, but “my children know magic is ḥarām”

Mūsa Richardson replies to this by saying:

Okay, will you allow your children to watch pornography because they know its ḥarām? Will you allow your children to eat pork and drink alcohol because they know it’s ḥarām? Or is our dīn about knowing what is ḥarām and avoiding it? Your children know it’s ḥarām and your children are obliged to stay away from it.”

Magic is true and people are affected by it. Be warned and protect your homes from such evil.