The Bible contains a clear definition of faith in Hebrews 11:1: “Now faith is the assurance of things hoped for, the conviction of things not seen.” Simply put, the biblical definition of faith is “trusting in something you cannot explicitly prove.”
This definition of faith contains two aspects: intellectual assent and trust. Intellectual assent is believing something to be true. Trust is actually relying on the fact that the something is true. A chair is often used to help illustrate this. Intellectual assent is recognizing that a chair is a chair and agreeing that it is designed to support a person who sits on it. Trust is actually sitting in the chair.