Most glorious Prince of the Heavenly Armies, Saint Michael the Archangel, defend us in our battle against "principalities and powers, against the rulers of this world of darkness, against the spirits of wickedness in the high places" (Eph. 6:12). Come to the assistance of men whom God has created in His likeness and whom He has redeemed at a great price from the tyranny of the devil. Holy Church venerates thee as her guardian and protector; to thee the Lord has entrusted the souls of the redeemed to be led into heaven. Pray, therefore, the God of Peace to crush Satan beneath our feet, that he may no longer retain men captive and do injury to the Church. Offer our prayers to the Most High, that without delay they may draw His mercy down upon us: take hold of "the dragon, the old serpent, which is the devil and Satan," bind him and cast him into the bottomless pit "so that he may no longer seduce the nations" (Apoc. 20:2).
His Holiness Leo XIII, reprinted on this feast of the Dedication of Saint Michael the Archangel, 29 September 2008.