It is not so much about faith in God as it is what we believe about Him that determines our faith.
Job, said these words, “what I have feared has come upon me”. What an awesome guy, God's own testimony of him says it all. “This man was blameless and upright; he feared God and shunned evil.”
Yet deep in his heart he yet needed to learn something of his Father. Was it all too good to be true? Can God really be as beautiful, wonderful and loving as I hoped? Job's own fear allowed the enemy to come before God and test Job. It was a fear based in the question of the character of his heavenly Father.
Job was already blameless and upright, shunning evil. So, in what way was he tested? His ultimate test was in what he believe about his God. Was he truly all that he wanted him to be, was he really that good? Was the Father's love beyond reproach? Job's answer “surely I spoke of things I did not understand, things too wonderful for me to know.” Job realized that the God he served was ultimately good even beyond his comprehension. “The LORD blessed the latter part of Job's life more than the first. “
God's promises are based in His character, if we will believe well of Him we will stand strong in what we believe from Him. For it is not the things in His hand that changes us it is that which in our Father's heart that make us truly rich. All flows from the wonder of who he is, the unchanging, ever loving character of our God.