Ninth letter to a nun.
“Let us think often that our only business in this life is to please God, that perhaps all besides is but folly and vanity. You and I have lived above forty years in religion (i.e. a monastic life). Have we employed them in loving and serving God, who by His mercy has called us to this state and that very end ? I am filled with shame and confusion when I reflect on one hand upon the great favours which God has done, and incessantly continues to do me ; and on the other, upon the ill use I have made of them, and my small advancement in the way of perfection.
Since by His mercy He gives us still a little time, let us begin in earnest, let us repair the lost time, let us return with a full assurance to that Father of mercies, who is always ready to receive us affectionately. Let us renounce, let us generously renounce, for the love of Him, all that is not He ; He deserves infinitely more. Let us think of Him perpetually. Let us put all our trust in Him : I doubt not but we shall soon find the effects of it, receiving the abundance of His grace, with which we can do all things, and without which we can do nothing but sin.
We cannot escape the dangers, which abound in life, without the actual and continual help of God ; let us then pray to Him for it continually. How can we be with Him but in thinking of Him often ? and how can we often think of Him, but by a holy habit which we should form of it ? You will tell me that I am always saying the same thing : it is true, for this is the best and easiest method I know ; and as I use no other, I advise all the world to it. We must know before we can love. In order to know God, we must often think of Him ; and when we come to love Him, we shall then also think of Him often, for our heart will be with our treasure. This is an argument which well deserves your consideration.”