I've been a pastor and a missionary for nearly 40 years. Have specialized in deliverance/healing and spiritual warfare.
The Bible tells us we don’t wrestle against flesh and blood, but against principalities, powers, and rulers of darkness. Yet many believers don't have any idea of this reality of wrestling (warfare) or have much training on how to prevail. Spiritual warfare is an often misunderstood or neglected aspect in the preparation for missions.