To that person, I'd just say: if you have Jesus Christ, you have reason to overflow with thanks, regardless of your situation.
I don't say this as a theoretician, though I'll not take you with me into the sloughs I've rented over the years. It's an ongoing lesson. So let me just turn to a better, a familiar friend to us all, Charles Spurgeon. One of the greatest, pithiest, truest, most encouraging little points he ever made was a meditation on Jeremiah 31:33 — "For this is the covenant that I will make with the house of Israel after those days, declares the LORD: I will put my law within them, and I will write it on their hearts. And I will be their God, and they shall be my people."
Spurgeon wrote this:
Christian! here is all thou canst require. To make thee happy thou wantest something that shall satisfy thee; and is not this enough? If thou canst pour this promise into thy cup, wilt thou not say, with David, “My cup runneth over; I have more than heart can wish”? When this is fulfilled, “I am thy God”, art thou not possessor of all things? Desire is insatiable as death, but he who filleth all in all can fill it. The capacity of our wishes who can measure? But the immeasurable wealth of God can more than overflow it. I ask thee if thou art not complete when God is thine? Dost thou want anything but God? Is not his all-sufficiency enough to satisfy thee if all else should fail? ...
[W]hat more canst thou hope for than the fulfilment of this great promise, “I will be their God”? This is the masterpiece of all the promises; its enjoyment makes a heaven below, and will make a heaven above.
There it is: "I will be their God" is "the masterpiece of all the promises; its enjoyment makes a heaven below, and will make a heaven above."
Think about it, Biblically. Make yourself, if your feelings aren't "there." Pray for God to help you think about it. What is the lot — the long-term lot — of the person who has everything but that promise to call his own? Family, friends, health, wealth... but God is not his God?
Then think: What is the lot — the long-term lot — of the person who has nothing but that promise to call his own? Little material good... God is his God?
We've worked at unfolding the treasures in that depository over the course of many posts; and we will do so, Lord willing, in many more. But that is it: if you have God as your God, through saving faith in Jesus Christ, then you have reason today for joy and gratitude. Though they matter, this central truth is true no matter how hard, happy, or non-existent your marriage; how thriving or struggling your church; how grateful or treacherous your children; how abundant or feeble your health; how many or few the candles on your birthday-cake.
Wherever you are, whatever your lot, look to Christ your Savior, Christ your Lord, and thank Him today.
You have reason, Christian friend.
I know this for a fact.