There are a few things you can do to stop having nightmares spiritually. First, make sure that you are living in accordance with God's will. This means living a life of purity and holiness. second, pray and ask God to protect you from evil spirits that may be causing your nightmares. third, bind the devil and all his works in the name of Jesus Christ. fourth, claim victory over your dreams in the name of Jesus Christ. fifth, declare war against the enemy in the spiritual realm by fasting and praying.