[Fundie is talking to another fundie who used to be a Wiccan.]
What you can do by playing with magic and occultism, is ruin your life. Magic/occultism is an open door in your life for Satan and his own to waltz into.

From the moment of your salvation, you entered into a spiritual war with the same dark powers you may have once had pacts and dealings with by way of your former practices.

White magic and black magic both have the same source. What may have once been an amiable relationship instantly became hostile by the side you've taken, regardless of your former magic practices, white or black.

By choosing Christ over them, you've made yourself an enemy of these forces. God is greater and mighty to save. Our Lord Jesus delivers us from our troubles and trials.

By dabbling again in the occult or practicing magic, you invite these forces God has driven out again into your life.

They're feeling betrayed, angry you won't be joining them, and any unfinished work or dedication you were maybe in the process of offering for services before your salvation will be held against you in the extreme.

Demons are very jealous and very vindictive.

By breaking your fellowship with God in this way to go play on the 'other' side, you're inviting every sort of disaster on yourself. Nevertheless your union with God should you have it, is forever.