But faith predated the Bible. There as no Bible yet written by anybody when Abraham risked all that he had, all that he was, all that he hoped to be to demonstrate his faith and obey YHWH.
Not necessarily. Moses saw a burning bush, it wasn't consumed. Faith was based on the revelation of God. Faith is based on hearing the calling of God although it is sometimes unseen or not heard.
Moreover, and this is all important, true faith must be based solely on scriptural facts, for faith cometh by hearing, and hearing by the word of God (Rom. 10:17). Unless our faith is established on facts, it is no more than conjecture, superstition, speculation or presumption.
Hebrews 11:1 leaves no question about this: Faith is the substance of things hoped for, the evidence of things not seen. Faith standing on the facts of the Word of God substantiates and gives evidence of things not seen. And everyone knows that evidence must be founded on facts. All of us started on this principle when we were born againour belief stood directly on the eternal fact of the redeeming death and resurrection of our Lord and Saviour Jesus Christ, as recorded in I Corinthians 15:1-4. This is the faith by which we began, and it is the same faith by which we are to stand (16:13), walk (II Cor. 5:7) and live (Gal. 2:20). As ye have therefore received Christ Jesus the Lord, so walk ye in him (Col. 2:6).
https://bible.org/seriespage/faith