On Gratitude:

"Gratitude is a form of intercession. Only it must not be like the gratitude of the Pharisee, who condemned others and justified himself (Luke 18:11). On the contrary, it must make one regard oneself as a greater debtor than all other men; one gives thanks in astonished bewilderment because one understands God's unutterable restraint and forbearance."


St. Peter of Damascus.