Understanding is the reward of faith. Therefore seek not to understand that thou mayest believe, but believe that thou mayest understand. –St. Augustine
Understanding is the sure and clear knowledge of some invisible thing. –St. Bernard
Thus understanding and love, that is, the knowledge of and delight in the truth, are, as it were, the two arms of the soul, with which it embraces and comprehends with all the saints the length and breath, the height and depth, that is the eternity, the love, the goodness, and the wisdom of God. –St. Bernard
Listen and attend with the ear of your heart -St. Benedict
We judge all things according to the divine truth. – St. Augustine
A scrap of knowledge about sublime things is worth more than any amount about trivialities. –St. Thomas Aquina
In so far as divine love beautifies our souls. And makes us pleasing to His divine Majesty, it is called grace; in so far as it gives us strength to do good, it is called charity; but when it reaches such a degree of perfection, that it makes us not only do the good, but do so carefully, frequently and readily, then it is called devotion. –St. Francis de Sales
Charity and devotion differ no more, the one from the other, than the flame from the fire. –St. Francis de Sales
Devotion is a certain act of the will by which man gives himself promptly to divine service. –St. Thomas Aquinas
It is better to say one Our Father fervently and devoutly than a thousand with no devotion and full of distraction. —St. Edmund (Source:roman catholic man )