Nobody goes to a battle unprepared. Even the Lord Jesus Himself uses the imagery of preparing to go to war as an indispensable part of the strategy to win it: "Or suppose a king is about to go to war against another king. Won't he first sit down and consider whether he is able with ten thousand men to oppose the one coming against him with twenty thousand?" (Luke 14:31) This is the same thing as well in the ministry of spiritual liberation and exorcism. The priest on behalf of the whole Church, the Mystical Body of Christ, in the name of her Savior and Lord Jesus Christ, goes to wage war against the devil and his legions. And he can not just go and attack without preparing himself for the battle. To do so would not only be foolish but also dangerous. Therefore, he prepares himself spirituality seeing to it that he is fully cloth in the armor that would protect him from the vicious attacks of the enemy. And that he has all the weapons given to him by Christ and the Church to use against the vile creature.
"Be strong in the Lord and in his mighty power. Put on the full armor of God, so that you can take your stand against the devil’s schemes. For our struggle is not against flesh and blood, but against the rulers, against the authorities, against the powers of this dark world and against the spiritual forces of evil in the heavenly realms. Therefore put on the full armor of God, so that when the day of evil comes, you may be able to stand your ground, and after you have done everything, to stand. Stand firm then, with the belt of truth buckled around your waist, with the breastplate of righteousness in place, and with your feet fitted with the readiness that comes from the gospel of peace. In addition to all this, take up the shield of faith, with which you can extinguish all the flaming arrows of the evil one. Take the helmet of salvation and the sword of the Spirit, which is the word of God." (Ephesians 6:10-18)Concretely, his preparation consists in making a good sacramental confession, reverent celebration of Holy Mass, meditation on the Word of God, mortification of the senses, fasting, prayer to Our Blessed Lady the Immaculate Virgin Mother of God seeking her maternal assistance and protection, prayers to one's patron saints, in my case --Sts. Joseph, Nicholas, Dominic de Guzman, Thomas Aquinas, Dominic Savio, Carlo Acutis, all Dominican Saints and Blesseds, prayer to Sts. Michael, Gabriel, Raphael and the Holy Angels to assist and fight for and in behalf of the exorcist and the afflicted against the legions of unclean spirits. In truth the exorcist never battles alone. He is united with the whole Church both in Heaven and on Earth. During the course of the ministry the assistance of these heavenly friends are very evident.