Faith means believing in and obeying God, which requires relying on what we cannot see—God’s promises, provisions and concern for us. An inner attitude alone does not define faith, though. For faith to be present, action is required. Faith proves itself by obedience to the Lord.
The writer of Hebrews expressed faith in two directions: faith toward future things (what we hope for) and faith toward invisible things (what we do not see). When we are certain God is in control of these areas (and we live like he is in control), that’s faith.
The two sides of faith—assurance and expectation—can be seen in the lives of those listed in this chapter. They had strong convictions about unseen present realities. They also had a strong assurance that God’s promises would be fulfilled—even in the face of evidence that seemed to suggest otherwise (see, for example, Heb 11:11).
Ultimately, the way we see God will determine the shape of our faith. If we see a big, faithful, all-powerful God, then our faith will rise to those levels. If, on the other hand, we see a smaller God, a distant or less active God, then faith will plateau at those levels.