I actually wrote this nearly two years ago, but never posted it because the Spirit prompted me not to. I've made a few edits from the original draft and I hope it is encouraging to you.

Growing up in the Church I've heard the account of the children of Israel wandering in the desert for forty years probably more than forty times. I don't know if you're like me, but their disobedience always made me wonder. How could they see God bring plague after plague, part the red sea, and go before them in a cloud and still question Him? They seemed like the most ungrateful and frustrating people ever. To a certain degree, as I've aged and matured I've started to see that I am kinda like them, but not til recently did I realize that I am EXACTLY like them. I read this in Psalm 78:17-19

Yet they sinned still more against him,
rebelling against the Most High in the desert.
They tested God in their heart
by demanding the food they craved.
They spoke against God, saying,
"Can God spread a table in the Wilderness?"

Asaph could have said, "They questioned God," but he didn't. He said, "They spoke against God." He could have used the word "doubt" or "worried", but he didn't. By the Holy Spirit, Asaph equated questioning the provision of God with the words "sinned", "rebelling against", "tested God", and "spoke against." It really hit me that when I worry, doubt, fret, or question I am doing the very same thing that these people did. I worry, doubt, fret, and question a lot sometimes. Just like Israel, I have a very real story and examples of God miraculously saving me from slavery and guiding me through many perilous times. Yet, I sin and rebel against him by worrying about the future and many other things. This makes me very thankful for the grace I have been given through Jesus Christ. I really do need Jesus every day to save me from myself. I am so thankful that God is merciful and that He leads me despite my sin and continued rebellion.
So, what do we do when we start to get anxious or when we want to question God? We remember that God wants us to pour our hearts out to Him because cares for us (1 Peter 5:7) without grumbling or questioning (Philippians 2:14). Most of all, we remember His Word and promises. When I am anxious I have a verse that I flinch to, to remind me of God's provision. I encourage you to memorize it as well. Isaiah 41:10 says

Do not fear, for I am with you;
Do not anxiously look about you, for I am your God.
I will strengthen you, surely I will help you,
Surely I will uphold you with My righteous right hand.

Travis