We live in a busy world! It's easy to get distracted, lose focus, and forget to spend time with God. It is during those busy moments that we get anxious and fearful. Then, we start worrying, doubting, and trying to be in control. When we try to control too much, though, we tend to become even more anxious. Our experience tells us that if we put our faith in ourselves, we will never be at peace.
In this Psalm, God Himself speaks. He is reminding us that He alone is the Sovereign God on earth and in heaven! While God enjoys our quiet time with Him in prayer, this stillness we are called to is not in physical movement but in our mind. He is calling us to stop fighting and surrender ourselves to Him. 
In God's Word, we see that He's the supreme authority. In God's Word, we see that He is alive and still in control of all the affairs of the world. Knowing God is God means that we recognize, acknowledge, and admit His supremacy. 
No matter what's going on in your life today, remember that God is still in control. Let your mind be still, and know that He is God!

Dear Heavenly Father, forgive me for getting so busy trying to control the things that are going on in my life that I forget about the fact that You are the Sovereign God over everything. Please take away my fears and worries, and replace them with faith and trust. You truly are our loving, caring, and all-powerful Father. Thank You for being my refuge and strength. 
In Jesus's name I pray. Amen.