God arranged the plan of salvation with a fundamental purpose: that no one would have any grounds for boasting in a self-glorifying way. Self-delusion and self-righteousness are characteristic of us fallen creatures; the very root of sin is pride. The only way to break pride and allow God's grace to triumph is to admit the awesome truth: we're all in desperate need of God, of His forgiveness, of His love, of His Holy Spirit, and all of us need to abandon our pride, admit our need, and come to the foot of the Cross to receive mercy and forgiveness. And we need to stay there.
Ralph Martin The Fulfillment of All Desire: A Guidebook to God Based on the Wisdom of the Saints (p. 229).