We should give thanks. It's God's will, and it's really, really good for us:
"I would maintain that thanks are the highest form of thought; and that gratitude is happiness doubled by wonder." ~ G.K. Chesterton
"Would you know who is the greatest saint in the world: It is not he who prays most or fasts most, it is not he who gives most alms or is most eminent for temperance, chastity or justice; but it is he who is always thankful to God, who wills everything that God wills, who receives everything as an instance of God's goodness and has a heart always ready to praise God for it." ~ William Law
“Gratitude bestows reverence, allowing us to encounter everyday epiphanies, those transcendent moments of awe that change forever how we experience life and the world.” ~ John Milton
“A thankful heart cannot be cynical.” ~ A.W. Tozer
"If the only prayer you said in your whole life was, 'thank you,' that would suffice." ~ Meister Eckhart
"We pray for the big things and forget to give thanks for the ordinary, small (and yet really not small) gifts. How can God entrust great things to one who will not thankfully receive from Him the little things?" ~ Dietrich Bonhoeffer
“A sensible thanksgiving for mercies received is a mighty prayer in the Spirit of God. It prevails with Him unspeakably.” ~ John Bunyan
"Gratitude as a discipline involves a conscious choice. I can choose to be grateful even when my emotions and feelings are still steeped in hurt and resentment. It is amazing how many occasions present themselves in which I can choose gratitude instead of a complaint. I can choose to be grateful when I am criticized, even when my heart still responds in bitterness. I can choose to speak about goodness and beauty, even when my inner eye still looks for someone to accuse or something to call ugly." ~ Henri Nouwen
"If you are not content with what you have, you would not be satisfied if it were doubled." ~ Charles Haddon Spurgeon
"Receive every day as a resurrection from death, as a new enjoyment of life; meet every rising sun with such sentiments of God's goodness, as if you had seen it, and all things, new-created upon your account: and under the sense of so great a blessing, let your joyful heart praise and magnify so good and glorious a Creator." ~ William Law
"I thank Thee first because I was never robbed before; second, because although they took my purse they did not take my life; third, although they took my all, it was not much; and fourth, because it was I who was robbed and not I who robbed." ~ Matthew Henry
"When we were children we were grateful to those who filled our stockings at Christmas time. Why are we not grateful to God for filling our stockings with legs?" ~ G.K. Chesterton
“The careless soul receives the Father's gifts as if it were a way things had of dropping into his hand yet is he ever complaining, as if someone were accountable for the checks which meet him at every turn. For the good that comes to him, he gives no thanks—who is there to thank? At the disappointments that befall him he grumbles—there must be someone to blame!” ~ George MacDonoald
“Be joyful always; pray continually; give thanks in all circumstances, for this is God's will for you in Christ Jesus.” ~ Paul, the Apostle: I Thessalonians 5: 16–18
"Praise be to you, O LORD,
God of our father Israel,
from everlasting to everlasting.
Yours, O LORD, is the greatness and the power
and the glory and the majesty and the splendor,
for everything in heaven and earth is yours.
Yours, O LORD, is the kingdom;
you are exalted as head over all.
Wealth and honor come from you;
you are the ruler of all things.
In your hands are strength and power
to exalt and give strength to all.
Now, our God, we give you thanks,
and praise your glorious name.”
~ David, King of Israel: 1 Chronicles 29: 10 - 13