(Hebrews 11:1) Now faith is the substance of things hoped for the evidence of things not seen. (KJV)
Definition of faith: The Greek word for faith is pistis, when used as a verb it means, belief, firm persuasion, assurance, firm conviction, faithfulness
Faith is not of mathematical probability (meaning) you cannot work it out as you would do in a math equation. Faith is also not natural, it is beyond belief. Faith is spiritual it is a gift from God. We cannot command faith at will God has to bestow it upon us. God will continuously birth faith in the yielded believer, so that they know what he prefers.