When the devil and his minions are storming your door, the following prayer can give you strength.
Prayer to Saint Michael the Archangel
Saint Michael the Archangel, defend us in battle, be our protection against the wickedness and snares of the devil. May God rebuke him we humbly pray; and do thou, O Prince of the Heavenly host, by the power of God, cast into hell Satan and all evil spirits who wander through the world seeking the ruin of souls. Amen.