Jesus has warned us that there will be trouble in this world, and that peace is only in Him. It is only in Him that we can overcome the world, as He has overcome it.
Sadly, rather than overcome, some become what God has not planned for them. I am not spared by this becoming, it is and always been a constant struggle. And truly, one cannot lean on his own understanding. It is always fallible, no matter how well-thought, how smart it may seem, as God has proven time and again that His thoughts are not our thoughts.
It is only through faith that we can see what is unseen and find rest in His peace.