Witchcraft, magic, and other similar practices are very lucrative. In fact, the love of money is at the root of this evil just as it is all others.
There are always two spirits at work: the Holy Ghost and a satanic or false spirit. Witchcraft comes from a satanic spirit and opposes God's Spirit.
The Lord is the strength of His people. While it is true that we are called to do our part, God must add the necessary strength to accomplish the work.
