Chapter 9.
How we too may overcome pride.
And so we can escape the snare of this most evil spirit, if in the case of every virtue in which we feel that we make progress, we say these words of the Apostle: “Not I, but the grace of God with me,” and “by the grace of God I am what I am;” and “it is God that works in us both to will and to do of His good pleasure.” As the author of our salvation Himself also says: “If a man abide in me and I in him, the same bears much fruit; for without me you can do nothing.” And “Unless the Lord builds the house, they labour in vain that build it. Unless the Lord keeps the city, the watchman wakes but in vain.” And “Vain is it for you to rise up before light.” For “it is not of him that wills, nor of him that runs, but of God that has mercy.”
Source: Institutes (New Advent)