From Augustine's Confessions, Book IV:

"Return, sinners, to your heart" (Isa. 46:8 LXX), and adhere to him who made you. Stand with him and you will stand fast. Rest in him and you will be at rest. Where are you going to along rough paths? What is the goal of your journey? The good which you love is from him. But it is only as it is related to him that it is good and sweet. Otherwise it will justly become bitter; for all that comes from him is unjustly loved if he has been abandoned. With what end in view do you again and again walk along difficult and laborious paths (Wisd. 5:7)? There is no rest where you seek for it.