It is easier to grasp the mystery of evil if we focus on the angelic world mentioned in the Bible.
It is worth remembering that it wasn’t just the Queen of Angels who was subjected to a radical spiritual choice (Fiat, let it be done, or Non serviam, I will not serve), but the angelic spirits themselves were put to the test.
With a few quotes from Scriptures, Saint Thomas Aquinas teaches that the angels were created in a state of grace, but without yet seeing God. From the moment of their creation, the angels became aware of their own perfection, which brought them great joy and made them praise God, but they were soon called by their Creator to detach themselves from that beautiful initial state to rise higher, above themselves, to a supernatural destiny beyond what they could have imagined: to contemplate God face to face in an eternal and jubilant ecstasy of love (Rev 5:11).
Together with theologians like Saints Augustine and Gregory, Saint Thomas Aquinas also thinks that, in the same moment that they were thus called to Divine Life, God also revealed to them their future mission and place in the supernatural order, especially their dependence on the future Incarnate Word and His Mother, full of grace yet a simple human.
For their pure spirit, this certainly constituted a test, for it was tantamount to asking them to leave a reality beautiful and good in itself in order to submit to another paradoxical order that could only hold its coherence from Divine Love going beyond all the expectations of a created nature.
In order to adhere to such a plan, the angels had to abandon their limited judgment and trust their Creator, in an act of supernatural love producing merit, whereby they were given an opportunity to cooperate freely with God in attaining their destiny of eternal happiness.
Some mystics have maintained that at that moment of choice, the angels were strengthened in their act of abandonment to God by perceiving a glimpse of the immaculate being of their future Queen, at once so humble and so close to the Most High.
Adapted from: Spiritualite Chretienne
Prayer to the Guardian Angel:
Dear Angel at my side,
my good and loyal friend,
you have been with me since the moment I was born.
You are my own personal guardian,
given me by God as my guide and protector,
and you will stay with me till I die.
He who created you and me
gave me to you as your particular charge.
You assisted in great joy at my baptism,
when I became part of the Mystical Body of Christ,
and was made a member of the household of God
and an heir of heaven.
You saw the dangers that beset my path,
and, if I sinned,
it was in spite of you.
You envied me when Christ came to me in Holy Communion.
Even though you probably were there
among the angels that adored Him
the night that He was born,
you have not been able to receive Him as I can.
O, help me to appreciate these gifts!
Help me to realize, as you do,
with every fiber of my being,
that to serve Christ is to be a King!
Help me steadfastly to avoid evil
and do good and always guard my soul from sin.
Protect me as well from physical evils
as I go about my daily work.
You will be with me all my life,
and at the hour of my death.
Help me to face death bravely, patiently,
with great love of God,
knowing that it is only through death
that I can come to Him in heaven!
Then, come with me to my Judge,
and when the hour of my salvation comes,
take me home to my Father, God.