Faith requires absolute belief in principles, and it is ‘magical’ in its ability to make things happen. In mathematics, probability ranges from 0-1. When probability is 0, that event will not happen. When it is 0.9, it is very much likely to happen. But when it is 1, it is certain to happen. The chances of the event happening is not just likely but certain. In other words, we know for sure that the event will happen.
In the same vein, when belief becomes absolute, it seizes to be mere belief, it becomes Knowing, it becomes faith. If the belief is not absolute, that is if it is not 100%, then it is not faith and therefore will not possess the magical power of faith. Faith is knowing for certain that a benefit will come to pass, because you have made the necessary sacrifices, paid the appropriate price, observed and obeyed the requisite principle.
If you are not certain, then it would be a matter of probability. Even where that probability is as high as 0.999, the other part of 0.001 leaves room for doubt, fear, worry and anxiety. Faith has absolutely no room for any of these negative energies. These emotions, even in their minute forms, dilute faith and renders it powerless.