And Mary said: Behold the handmaid of the Lord: be it done to me according to thy word. And the angel departed from her. (Lk 1:38)
Occasionally, in human history, a person makes a decision that changes the course of history. In 1571, for example, it was the heroic decision of Don John of Austria to answer the call to arms of Pope St. Pius V against the Muslim Turks who threatened the whole of Christian Europe. If Don John had not answered the call, if he had not said "fiat" to Pope St. Pius V and then subsequently defeated the Muslim fleet at Lepanto, Europe would now be Muslim, ...and none of us would be here today.
But of all the decisions that have ever been made, the decision that had the most impact on history was the decision of a thirteen year old girl in Nazareth, in Galilee. By saying "fiat" to the will of God announced by the Angel Gabriel, Mary changed the course of history; she changed the universe ...she even changed heaven!
It was the greatest decision ever made. Greater than the decision of any king or emperor, greater than any mogul, general or politician:
And because Mary is our mother she cares for us as mother; procuring for us all that she can for our true happiness. All graces pass through the hands of Mary by her intercession: think of them!
These all came from Mary's "fiat".
For us priests, we can say that our priesthood came from Mary's "fiat". A priest is a man who shares in the Divine Priesthood of her Son (just as someone who is in a state of grace shares in the Divine Life). If Mary had not uttered her "fiat", there would be no Divine Priesthood on earth, there would be no Mass. There would be no priests, no Society of St. Pius X, no Archbishop Marcel Lefebvre who was called to God on this day in 1991.
But the power of the "fiat" of Mary did not come from the words, it came from that total gift of self to the will of God. Mary's “fiat” had such an astounding effect on heaven and the entire material universe because there was nothing of self in her "fiat", there was nothing held back in reserve for herself, unlike us, who, when we give to God, we always keep something for ourselves. For example when we make a sacrifice, we keep some comfort for ourselves like taking the smaller slice of cake rather than taking no cake at all! Or when we perform good works, we often look for just a little personal glory in our works as when we cast the slightest flash of a glance to see if anyone has noticed us.
On this feast of the Annunciation, let us offer thanks to the Blessed Virgin Mary for her “fiat” - begging from her the grace to utter our own. "Give what Thou enjoinest, and enjoin what Thou wilt" says St. Augustine in his Confessions. If only we would do this, we would change history too.