The Book of Job expresses a reality that we live every day: “Militia est vita hominis super terram – The life of man upon earth is a warfare” (7:1). This daily struggle is a reflection of the prœlium magnum in Heaven, between St. Michael’s army and the insurgent angels. Under the standard of the Lord, the Holy Archangel proclaimed the divine magnificence: “Quis ut Deus? – Who is like unto God?”; under the standard of darkness, Lucifer exhaled revolt and insubordination, “Non serviam! – I will not serve!” This antagonism, however, did not end with the precipitation of the evil angels into the infernal abyss; it was carried over into earthly life, as a continuation and consummation. Indeed, the Apostle asserts that “For we are not contending against flesh and blood, but against the principalities, against the powers, against the world rulers of this present darkness, against the spiritual hosts of wickedness in the heavenly places” (Eph 6:12). For St. Thomas Aquinas (cf. Summa Theologiæ, I, q.114, a.1), this struggle has its origin in the evil of the devil who “has sinned from the beginning” (1 Jn 3:8); nevertheless, the ordination of things to their ultimate end comes from God, who knows how to permit evil so as to draw good from it. From a merely human perspective, the significance of these divine mysteries remains hidden. In this sense, Christ’s mission on earth was a great reconquest. At every moment Jesus fought against diabolical activity, whether in the form of temptations, vexations or possessions. This crusade against the devil constituted the very essence of His mission: “God anointed Jesus of Nazareth with the Holy Spirit and with power; how He went about doing good and healing all that were oppressed by the devil, for God was with Him” (Acts 10:38). However, although the Redemption was a great setback for the spirits of darkness, they persist in their task of tempting the children of light. The good Angels, on the other hand, are literally “on guard” to help us in our battle against the “prince of this world” (Jn 16:11). The devil’s weapons are well known, as are his allies: the world and the flesh. Moreover, his tactical resources, such as surprise and dissimulation, have already been scrutinized and have become timeworn; in fact, he often disguises himself as an “angel of light” (2 Cor 11:14). These artifices are available to any army; however, only the children of light can make use of what no human power can offer, namely, grace. This is the secret of victory: union with Her who is “full of grace” (Lk 1:28). Now, if the core of the demons’ revolt is summed up in the revolutionary attitude of “non serviam”, the counter-revolution of the good can only be distinguished by detached service, by the “serviam”, in imitation of Mary Most Holy, “the handmaid of the Lord” (Lk 1:38). Accordingly, there is no act more exorcistic than to consecrate oneself as a slave to Incarnate Wisdom through the hands of the Queen of Angels, for She, through her offspring, will definitively crush the head of the Serpent (cf. Gn 3:15). Then these “apostles of the latter times”, united with the Angels and the Saints, will proclaim with one voice: “Who is like unto Mary?” ◊  
Detail of “The Final Judgement”, by Fra Angelico - San Marco Museum, Florence (Italy)