People cannot receive the gospel when their minds have been veiled by witchcraft. We are beginning a work in prayer that the Lord will finish at His coming when He removes the veil that has been placed on the nations. God has perfected praise to still, stop and shut down the enemy. An acquaintance of ours had a vision of marching angels. The demons before them were very active, but when the angels sang and praised the Lord, the demons were immobilized.
All witchcraft is based on making curses.
We have been given the power in Jesus' name to break curses. Not all illnesses are the direct result of curses, but we always break curses first when praying for someone who has an infirmity. Many times when there is a demonic attack the doctors will find no medical cause for the affliction. In Psalm 35 David asks the Lord to send His angels to chase his enemies. I lerned from a deliverance church that this was the most effective tactic they used.