The Institutes, Book 12
Even the Effort Needs God’s Grace
So, in keeping with their teaching and instruction, we ought to press on toward it and be diligent in fasting, vigils, prayer, and the crushing of heart and body, so that all these things are not made useless by an attack of this sickness. For we ought to believe not only that we cannot secure this perfection itself by our own efforts and labors, but also that we cannot even do the things we practice for its sake, that is, our efforts and labors and desires, without the help of God’s protection and the grace of his inspiration, correction and encouragement. These he usually pours into our hearts either through someone else or by coming to visit us himself.