What can flesh do to me?

Psalms 56:3-4

Whenever I am afraid, I will trust in You. In God (I will praise His word), in God I have put my trust; I will not fear. What can flesh do to me?

Mathew 6:20-21

but lay up for yourselves treasures in heaven, where neither moth nor rust destroys and where thieves do not break in and steal. For where your treasure is, there your heart will be also.

Flesh can do NOTHING to us, not if we trust in the Lord. Sure, life comes with situations that trouble us, but we must put our trust in the Lord. But God doesn't want us to just trust Him in the hard times, NO! God wants us to trust Him through the little things as well.
Us being humans, we usually learn things through practice. So when God wants us to trust Him in everything, He means not only the BIG but also the small. Just think it through, once we can put our trust in Jesus through the littlest of things, when the big problems come around we won't want to do anything else but trust in Jesus. We must learn to put our trust in Him in EVERYTHING.
Jesus doesn't just stay on the throne until we're in trouble, and then He comes to save us. No, Jesus is with us till the end of the age (Mathew 28:20). He is with me right now as I write this blog. He is with you right now as you read this post. He is with us wherever we are and in whatever we do. He knows when we'll need Him, and He comes to our rescue. He is our very present help in trouble (Psalms 46:1).
God wants us to learn to trust in Him. The Bible is filled with many verses about trust, here are a couple.
Proverbs 3:5-6

Trust in the Lord with all your heart, and lean not on your own understanding; in all your ways acknowledge Him, and He shall direct your paths.

Once we put our trust in the Lord, we don't need to figure much out. As we lean on Jesus, He will open up our minds with the correct way to walk down in order to get past that problem.
Hebrews 13:5-6

Let your conduct be without covetousness; be content with such things as you have. For He Himself has said, "I will never leave you nor forsake you." So we may boldly say: "The Lord is my helper; I will not fear. What can man do to me?"

When we go through problems we wonder why others are having such a carefree life. We must focus on trusting that God has a different plan for us; that He has the best in plan for us.
Let us learn to trust in God in everything. This practice will help us find peace in Him.