Thanksgiving, the giving of thanks, gratitude. From eu (well) + charis (grace) — literally 'good grace' or 'gracious response.' Eucharistia is both the attitude of gratitude and the act of giving thanks, particularly in worship. It gives its name to the Eucharist (communion).
Paul commands, 'In everything give thanks' (1 Thessalonians 5:18). Thanksgiving is not optional but the proper posture of one who has received grace. At the Last Supper, Jesus 'gave thanks' (eucharistēsas) before breaking bread — this act of thanksgiving became the name of the central Christian meal. Ingratitude is listed among the marks of a fallen humanity (Romans 1:21). The redeemed life is fundamentally a thankful life.