Matthew 5:16: Let your light so shine before men, that they may see your good works, and glorify your Father which is in heaven.
Psalms 19:12b: . . . cleanse thou me from secret faults.
Mark Guy Pearse:
The world wants men who are saved from secret faults. The world can put on an outside goodness and go very far in uprightness and morality, and it expects that a Christian shall go beyond it, and be free from secret faults. A little crack will spoil the ring of the coin. . . . The world expects, and rightly, that the Christian should be more gentle, and patient, and generous, than he who does not profess to be a disciple of the Lord Jesus. For the sake of those who take their notion of religion from our lives, we need to put up this prayer earnestly, Cleanse thou me from secret faults.