If he was a man of God, he wouldn't be committing adultery. And if he did, he would repent that act. Witchcraft did not cause this (he did), and until he repents and admits what he did, God is not going to sanction him. The only way he can be forgiven is to be truly sorry and ask for forgveness. You will not help him if you make excuses such as witchcraft to excuse his adultery. I pray that God is with you and leads you to the orrect action in this case.