When really weak in ourselves, and conscious of that weakness, we are in the state suited to the manifestation of the power of God. When emptied of ourselves, we are filled with God. Those who think they can change their own hearts, atone for their own sins, subdue the power of evil in their own souls or in the souls of others, who feel able to sustain themselves under affliction, God leaves to their own resources. But when they feel and acknowledge their weakness, he communicates to them divine strength.
Charles Hodge