Except for attributing Hebrews to Pauline authorship, Steve has a few excellent posts on faith and faithfulness. (here and here) I believe that Steve is right and would encourage you to read his posts. (Try my tags here and here)
But rather than mere cognitive assent to an unproved proposition, I think the best way of viewing the semantic center of pistis is in the words commitment, dependence, trust, and devotion. As I said, ”belief” plays a part, since we devote ourselves to things we believe in, and believe in things we are devoted to.
I agree – faith(fulness) is more about a conscious acceptance of the things set before you; it is about an active movement towards God and a daily walk. But, you know my position – go read Steve’s.