In Whom Do You Believe?
One way you can differentiate a person of calmness, composure, contentment and confidence from those who lack these elements is who they believe is in control. The other part of the equation is understanding if the one who is in control can and will deliver on their promises and if they have the resources to do so.

Jesus recognized that his disciples had troubled hearts. He had seen it many times. When a crowd needed to be fed, they were troubled. When they were in a storm on the sea of Galilee, they were troubled. When Jesus was arrested, tried, and crucified, they were troubled. He had a message for them. It had everything to do with who they trusted.
“Let not your hearts be troubled. Believe in God; believe also in me. In my Father’s house are many rooms. If it were not so, would I have told you that I go to prepare a place for you? And if I go and prepare a place for you, I will come again and will take you to myself, that where I am you may be also.” John 14:1-3
Other Helpful Reminders…
The following quotes are from John Blanchard’s, The Complete Gathered Gold: A Treasury of Quotations for Christians (Webster, New York; Darlington, England: Evangelical Press, 2006.)

“Keep your heart with all diligence and God will look after the universe.” – A. W. Tozer, p. 287.
“Panic is the sinful failure to apply our knowledge of God to particular problems.” – Maurice Roberts, p. 212.
“Nothing is more offensive to God than disbelief of his promise and despair of the performance of it because of some difficulties that seem to lie in the way.” – Matthew Henry, p. 662.
All scripture passages are from the English Standard Version except as otherwise noted.
