If you feel a natural hesitation when confronted with the more profound mysteries of faith, take courage, Christian soul, and say not contentiously but with loving submission: ‘How can these things be?’
Let your question be a prayer, let it be an expression of love, piety, and humble longing.
Seek not to explore the heights of the divine majesty, but to find salvation in the saving deeds of God our Saviour.
Then the Messenger of God’s great design will reply: When the Paraclete comes, whom I shall send you from the Father, he will remind you of everything and teach you all truth.
Even as no one knows the thoughts of man except the spirit of the man that is within him, so no one comprehends the thoughts of God except the Spirit of God.
Hasten therefore to share in the Holy Spirit. He is with you when you call upon him; you can call upon him only because he is already present.
When he comes in answer to your prayer, he comes with an abundance of divine blessings. He is the river whose streams give joy to the city of God.
If when he comes he finds you humble, silent, and trembling at the words of God, he will rest upon you and reveal what God the Father has hidden from the wise and the prudent of this world.
You will then begin to understand the things holy Wisdom could have told his disciples on earth, but which they were unable to bear until the Spirit of truth came who was to teach them all truth.
We cannot hope to learn from the lips of any man truths that Truth himself could not convey. For he himself has told us: God is spirit and those who worship him must worship in spirit and truth, so those who wish to know him must seek understanding of their faith and perception of its pure and simple truth only through the Holy Spirit.
In the darkness and ignorance of this life the Holy Spirit is the light that enlightens the poor in spirit, the love that draws them on, the sweetness that attracts them, their access to God, the love of the loving.
The Spirit is devotion and piety. From one degree of faith to the next the Spirit reveals to believers the justice of God, so that grace follows grace, and the faith that comes from hearing gives place to a faith enlightened by understanding.
William of Saint-Thierry (c.1075/80-1148): The Mirror of Faith (PL 180:384); from the Monastic Office of Vigils for Friday of the Seventh Week of Eastertide Year 2.