Summary: People question the sovereignty of God...but that doesn’t change His sovereignty!
21Have you not known? Have you not heard? Has it not been told you from the beginning? Have you not understood from the foundations of the earth? 22It is he who sits above the circle of the earth, and its inhabitants are like grasshoppers; who stretches out the heavens like a curtain, and spreads them like a tent to live in; 23who brings princes to naught, and makes the rulers of the earth as nothing. 24Scarcely are they planted, scarcely sown, scarcely has their stem taken root in the earth, when he blows upon them, and they wither, and the tempest carries them off like stubble. 25To whom then will you compare me, or who is my equal? says the Holy One. 26Lift up your eyes on high and see: Who created these? He who brings out their host and numbers them, calling them all by name; because he is great in strength, mighty in power, not one is missing. 27Why do you say, O Jacob, and speak, O Israel, “My way is hidden from the LORD, and my right is disregarded by my God”? 28Have you not known? Have you not heard? The LORD is the everlasting God, the Creator of the ends of the earth. He does not faint or grow weary; his understanding is unsearchable. 29He gives power to the faint, and strengthens the powerless. 30Even youths will faint and be weary, and the young will fall exhausted; 31but those who wait for the LORD shall renew their strength, they shall mount up with wings like eagles, they shall run and not be weary, they shall walk and not faint.
Why, do you suppose, men question the existence of God? And why do they act as if His sovereignty – that He alone is in charge – is irrelevant? And why do you suppose they do that when they are most in need of God?
Despite the rampant unbelief and impunity with which many treat God, it does not change the fact of God’s existence or His sovereign will. Eternal truth never changes based upon the approval or disapproval of men; God is God, and we are not!
I suspect most unbelief comes from two sources:
1. the arrogance of men who just can’t settle for a God they can’t see or control.
(Frankly, it doesn’t make a whole lot of sense to me to depend upon a God which you control, because the first time you need this “god” for something bigger than you, well, you are kind of out of luck. If you control him, how is he going to handle something you can’t? Personally, I need a God who is bigger than my finite mind and abilities, and my problems!)
A second source of unbelief is…
2. the extreme pain of men who are in such dire circumstances they cannot think straight.
In the movie “Man On Fire” John Creasy (played by Denzel Washington) was just such a man.
John Creasy, former CIA operative, has taken an assignment as bodyguard to a rich Mexican family to protect their daughter Pita. On his first day on the job, he must take her to school. Creasy has wrestled with suicide as he tries to face the guilt from some of the terrible things he did in his previous job.
In the film clip Creasy’s conversation with a nun at Pita’s school ends with him declaring his knowledge of God, but his unbelief in God’s willingness to have someone like him: “I am the sheep that got lost, Madre” is a powerful condemnation. For someone who knows the Word, Creasy doesn’t know the Father’s heart. 
Unbelief arrives in thousands of different packages and scenarios. It shows up in different lifestyles and is expressed in so many different ways it is difficult just to catalogue them. Today let’s assume the funnel narrows it down to the uneasy sense of betrayal one feels at being “left all alone in this great big world to fend for oneself”; in short, unbelief is a form of fear, an anger that the Creator doesn’t love me or care for me.
The nation of Israel felt that way (8th Century BC). They had been conquered and the city of Jerusalem was in ruins; the most capable citizens had been carried off to slavery. Their collective whining found its way into Isaiah’s words. Their defeat and shame turned to unbelief which expressed its anger towards a God they figured had abandoned them:
“GOD has lost track of me. He doesn’t care what happens to me” -- Isaiah 40:27b (TMSG)
There is a modern echo of this kind of thinking. It is found in the kind of argumentative questioning in which (so-called) sophisticated people want to engage. Well good…let’s engage! What kind of questions are the stuff of unbelief?