John 14:27 NKJV - "Peace I leave with you, My peace I give to you; not as the world gives do I give to you. Let not your heart be troubled, neither let it be afraid."
Here's another example where personal faith is to be applied. Jesus said He gives peace to His disciples and that the result would be that they would not "be troubled, neither...afraid." The question is, "Are you troubled and afraid?" Maybe the answer is "no" for the moment anyway, but you and I know that many Christians are now or have recently been afflicted with troubling thoughts due to troubling situations. The point is, Why are Christians troubled when Jesus said they shouldn't be?
Jesus knew troubling things would happen to His own. Note John 16:33 NKJV, "These things I have spoken to you, that in Me you may have peace. In the world you will have tribulation, but be of good cheer, I have overcome the world." He said the believer could be in "good cheer" during tribulation. Really? Yes, really!
Note Acts 20 where Paul was warned about impending persecution. Here are verses 23 and 24 NKJV, "...except that the Holy Spirit testifies in every city, saying that chains and tribulations await me. But none of these things move me; nor do I count my life dear to myself, so that I may finish my race with joy..." (Emphasis mine). How could Paul have joy in trials? He believed God personally! He knew Jesus said that his heart should not be troubled or afraid. He personally believed that and God gave him peace in the trials, so much so, that in 2 Corinthians 12:9, 10 NKJV he says, "And He said to me, 'My grace is sufficient for you for My strength is made perfect in weakness.' Therefore most gladly I will rather boast in my infirmities, that the power of Christ may rest upon me. Therefore I take pleasure in infirmities, in reproaches, in needs, in persecutions, in distresses, for Christ's sake. For when I am weak, then I am strong." (Emphasis mine). He personally believed that God would personally apply His peace to Paul in a personal way.
Personal faith in a personal God to apply His personal promises to me! Believe Him and He WILL do it!