Imitation of Christ

Multum contrariatur supernæ visitationi salsa libertas animi, et magna confidentia sui. Deus benefacit consolatinis gratiam dando, sed homo male facit non statim Deo cum gratiarum actione retribuendo. Et ideo non possunt in nobis dona gratiæ fluere, quia ingrati sumus auctori, nec totum refundimus fontali origini. Semper enim debetur gratia digne gratias agenti sive referenti. Auferetur ab elato, quod dari solet humili. 

Great is the difference between a visitation from above and false liberty of spirit and great confidence in self. God does well in giving us the grace of comfort, but man does ill in not immediately giving God thanks thereof. And thus the gifts of grace are not able to flow unto us, because we are ungrateful to the Author of them, and return them not wholly to the Fountain whence they flow. For grace is always the portion of him who is grateful and that is taken away from the proud, which ought to be given to the humble.

Imitation of Christ, II, 10:2