Fiat mihi secundum verbum tuum (Let it be done unto me according to thy word). The posture of humility and obedience, trust and love. Mary’s fiat, to me, is a reminder of the right posture of the heart in following God’s will.
With the right posture we guide ourselves to yield to the leading of the Holy Spirit. We lead our heart to do the right thing regardless how we feel. With the right posture, we find courage to make things right and with the right posture we overcome fear because we are assured of the presence of the Holy Spirit in our lives and with that we too, like Mary, can say Yes Lord, your will be done.