“Thou wilt keep him in perfect peace, whose mind is stayed on thee: because he trusteth in thee.” (Isaiah 26:3 KJV)
Because why? What part of trusting in Him brings perfect peace? As in trusting Him to handle the situation that would otherwise cause us to be unstable? Does one notice a fly while taking in a truly awesome sight? Perhaps we do not trust in Him for the express purpose of calming the storm, but rather because we see Him. We forget about the situation once we have the slightest bit of the presence of Jesus!
When it says our mind is stayed, is that like the entire construct of our thoughts are propped up on Him? Like the easel on which all the drawings that we design leans on Him? We are not at perfect peace because the trials are absent, but because we know Jesus. It is also true that Jesus is the only answer. The only real justice. The only one who can completely remake.
So, why does the issue that disturbs our peace seem so large? Perhaps it is that very issue which our mind is stayed on. If there is an issue, it is the natural state of a manager to work it over and over until it is resolved. Did you notice the verse said nothing about the issue? It only comments on the necessity of our mind being on God. How can our mind be on God when it is busy trying to fix something? Ah, there it is at last.
“Settle it therefore in your hearts, not to meditate before what ye shall answer: For I will give you a mouth and wisdom, which all your adversaries shall not be able to gainsay nor resist.” (Luke 21:14-15 KJV)