This came to me while I was contemplating a situation in my life where I was struggling to understand why I sometimes 'worry' over things I have surrendered to God. This is where a lot of us fall and stay down for a long time, unless we become enlightened inside of us to pick ourselves up by our believe and in the God we have placed our trust in.
Because of the way the world is and how we have seen/heard about how people treat each other, the wickedness we see and hear or even experienced, have led us to be quick in our respond to a threat than a promise. This is not because we do not 'know' that God is always willing to rescue us when we call on him, but because we have failed to separate the size of the problem, who is responsible for it and the ability of God.
The human nature is "naturally" wicked and full of revenge and spite thereby offering a fertile ground for unbelief, doubt, fear and worry. because when you have been bad towards someone else its only natural to expect the same. So we are constantly battling the notion of "to be kind or not be kind", "to forgive or not to forgive", to love or not to love".