1 Peter 5:8 Be calm but vigilant, because your enemy the devil is prowling round like a roaring lion, looking for someone to eat. In this spiritual battle the is a very important alliance between Mary, the Queen of the Universe and St. Michael the Archangel. The Book of Revelation 12 Now a great sign appeared in heaven: a woman, adorned with the sun, standing on the moon, and with the twelve stars on her head for a crown…Then a second sign appeared in the sky, a huge red dragon which had seven heads and ten horns, and each of the seven heads crowned with a coronet. Its tail dragged a third of the stars from the sky and dropped them to the earth, and the dragon stopped in front of the woman as she was having the child, so that he could eat it as soon as it was born from its mother. The woman brought a male child into the world, the son who was to rule all the nations with an iron scepter, and the child was taken straight up to God and to his throne…And now war broke out in heaven, when Michael with his angels attacked the dragon. The dragon fought back with his angels, but they were defeated and driven out of heaven. The great dragon, the primeval serpent, known as the devil or Satan, who had deceived all the world, was hurled down to the earth and his angels were hurled down with him…Let the heavens rejoice and all who live there; but for you, earth and sea, trouble is coming - because the devil has gone down to you in a rage, knowing that his days are numbered.’ …Then the dragon was enraged with the woman and went away to make war on the rest of her children, that is, all who obey God's commandments and bear witness for Jesus.
St Faustina experienced the help of St. Michael: “September 29. On the feast of St Michael the Archangel, I saw by my side that great Leader, who spoke these words to me – ‘The Lord has ordered me to take special care of you. Know that you are hated by evil; but do not fear – Who is like God!’. And he disappeared. But I feel his presence and assistance.” (Diary of St Faustina, para.706)
“O glorious Archangel St. Michael, Prince of the heavenly host, defend us in battle, and in the struggle which is ours against the Principalities and Powers, against the rulers of this world of darkness, against spirits of evil in high places (Eph 6:12). Come to the aid of men, whom God created immortal, made in his own image and likeness, and redeemed at a great price from the tyranny of the devil (Wis 2:23-24, 1 Cor 6:20).
Fight this day the battle of the Lord, together with the holy angels, as already thou hast fought the leader of the proud angels, Lucifer, and his apostate host, who were powerless to resist thee, nor was there place for them any longer in Heaven. But that cruel, that ancient serpent, who is called the devil or Satan, who seduces the whole world, was cast into the abyss with all his angels (Rev 12:7-9).
“Behold, this primeval enemy and slayer of man has taken courage. Transformed into an angel of light, he wanders about with all the multitude of wicked spirits, invading the earth in order to blot out the name of God and of his Christ, to seize upon, slay and cast into eternal perdition souls destined for the crown of eternal glory. This wicked dragon pours out, as a most impure flood, the venom of his malice on men of depraved mind and corrupt heart, the spirit of lying, of impiety, of blasphemy, and the pestilent breath of impurity, and of every vice and iniquity.
“These most crafty enemies have filled and inebriated with gall and bitterness the Church, the spouse of the Immaculate Lamb, and have laid impious hands on her most sacred possessions (Lam 3:15). Arise then, O invincible prince, bring help against the attacks of the lost spirits to the people of God, and bring them the victory. Amen.”