At least this is what Oswald Chambers believes as he has written in his devotional "My Utmost For His Highest." Why do you think this is so? I think it is because we have taken our eyes off of Jesus and put them on ourselves instead. We no longer trust Him to take care of us and don't really believe that He is in control. We feel the need to complain about our circumstances, instead of trusting Him with them and we really don't believe that "He works all things out for good to those who love Him and are called according to His purposes."
Therefore, "Turn your eyes upon Jesus. Look full in His wonderful face. And the things of earth will grow strangely dim in the light of His glory and grace." Stop worrying. Stop feeling sorry for yourself. It only leads to bad things. Renew your mind with God's truths and trust Him. He alone is worthy.