One of my favorite Bible stories in the Old Testament since I became an adult (long ago, by the way) is about King Nebuchadnezzar. Although he was the ruler of a pagan nation, God teaches us a simple and yet powerful truth through this man's story.
King Nebuchadnezzar had a very troubling dream that none of his wise men could interpret until a Jewish exile named Daniel was ushered into his throne room. Through the power of God, Daniel was able to make sense of King Nebuchadnezzar's dream which, to put it briefly, was a prediction of profound loss of mental stability and as a result of that, loss of his position as king.
At the end of the interpretation, Daniel urged the king to turn away from his sins, repent, and live right. If he were to do this, Daniel told him that there may possibly be "a continuance of lengthening of your peace and tranquility and a healing of your error." (Daniel 4:27, Amplified Bible)
King Nebuchadnezzar apparently did not follow that counsel because after twelve months had passed, he was admiring all of his kingdom and giving himself credit for his abundance. A voice from heaven spoke aloud to say that his kingdom had departed from him.
With startling speed his mind deteriorated to where he became like an animal, driven from among people and eating grass like a cow. He lived outdoors and his hair became long like feathers and his fingernails took on the appearance of birds' claws. He remained in this state of insanity for a full seven years.
At the end of that time, for whatever reason or circumstance, the man lifted his eyes to heaven. The right use of his mind returned to him. He blessed God, praising and honoring Him as he acknowledged God's everlasting dominion that endures from generation to generation.
When the king's sense of reasoning and understanding were returned to him, he was also (amazingly) given back the majesty and splendor of his kingdom. His counselors and lords sought him out and he was reestablished with more greatness than he had before.
... I, Nebuchadnezzar,
raised my eyes toward heaven,
and my sanity was restored.
Then I praised the Most High;
I honored and glorified him
who lives forever."
New International Version
When the state of our world is a mess, current events threaten our peace of mind, and we feel incapable of making any positive difference, I am comforted that our Sovereign God is in control. That assurance brings calm to my personal world.