Belief can not exist with out some element of doubt because it is not fixed i.e. an unconfirmed or magical thought
Belief is not knowing So faith becomes unstable
Why does one cling to god ? To feel safe but if you have faith you do not hold onto anything anymore i.e. What esoteric Christianity refers to as the cloud of unknowing ….fixed in he mystery beyond doubt

The Cloud of Unknowing) is an anonymous work of Christian mysticism written in Middle English in the latter half of the 14th century. The text is a spiritual guide on contemplative prayer in the late Middle Ages. The underlying message of this work suggests that the way to know God is to abandon consideration of God's particular activities and attributes, and be courageous enough to surrender one's mind and ego to the realm of "unknowing", at which point one may begin to glimpse the nature of God.