this prayer was composed by Pope Leo XII after he had this vision-
The guttural voice, the voice of Satan in his pride, boasted to Our Lord: "I can destroy your Church."
The gentle voice of Our Lord: "You can? Then go ahead and do so."
Satan: "To do so, I need more time and more power."
Our Lord: "How much time? How much power?
Satan: "75 to 100 years, and a greater power over those who will give themselves over to my service."
Our Lord: "You have the time, you will have the power. Do with them what you will."
In 1886, Pope Leo XIII decreed that this prayer to St. Michael be said at the end of "low" Mass (not "high", or sung Masses) throughout the universal Church, along with the Salve Regina (Hail, Holy Queen); and the practice of the congregation praying these prayers at the end of Mass continued until about 1970, with the introduction of the new rite of the Mass.
John Paul II and St. Michael
However, at the end of his Angelus message given in St. Peters Square, Sunday, April 24, 1994, Pope John Paul II urged Catholics to recite this prayer to Saint Michael once again:
"The prayer can fortify us for that spiritual battle about which the Letter to the Ephesians speaks [of]: "Finally, draw your strength from the Lord and from his mighty power."(Ephesians 6:10). And to this same battle that the Book of the Apocalypse refers [to], recalling in front of our eyes the image of St. Michael the Archangel (cf. Revelations 12:7). Surely, this scene was very present to Pope Leon XIII, when, at the end of the previous century, he introduced to the entire Church a special prayer to St. Michael: St. Michael the Archangel, defend us in battle; be our protection against the wickedness and snares of the devil
"Even if today this prayer is no longer recited at the end of the Eucharistic celebration, I invite all to not forget it, but to recite it in order to obtain help in the battle against the forces of darkness and the spirit of this world." - taken fom michaeljournal.org
I have received a St Michael's prayercard after writing to a newspaper religion columnist when i was still a child. I have kept St Michael's picture eversince. Years ago, I had a very frightening experience when I felt i will surely die at the hands of a frightening man who turned out to be the same man who harassed a number of women according to the policemen who interviewed me. I have called out to Heaven to help me, esp St Michael, our Blessed Mother and St Joseph. soon, as the man (who must be over 6ft tall) was approaching me he looked so confused and he was looking up behind me as if he was seeing very tall people. he walked past me and ran away. Surely i felt the presence of the angels protecting me esp of St Michael.
when the policemen arrived, the man was long gone. they interviewed me and said to me that i was very lucky.
I have been praying to St michael eversince. and finally i was able to visit St Michael's cave in Mont-Saint-Michel, Italy to personally say thanks to him.
I urge everyone in CM to continue praying to St Michael for the protection of the Universal Church and the Pope and all the priests. St Francis of Assissi had great devotion to St Michael, offering forty days of fasting in his honor. St Francis often said ' St Michael should be honored more often as he has the office of presenting souls to God' - taken from angels and devils.