Final answer:
Hebrews 11:1 defines faith as the substance of things hoped for and the evidence of things not seen, emphasizing the concept of believing in what is not immediately visible or provable.
Step-by-step explanation:
According to Hebrews 11:1, faith is defined as 'b) the substance of things hoped for, the evidence of things not seen'. This means that faith is both the foundation or confidence of what we expect and the conviction of the reality of things that we cannot perceive through our senses. This verse suggests that faith goes beyond what we can empirically prove and requires a degree of trust in things that are not immediately evident to us.