How does the Bible define and characterize faith?

Faith is trusting not in human might or human power but in the Spirit of God (Zechariah 4:6). It is the empty hand that takes hold of grace precisely where we are weak, so that the power of Christ dwells in us and is perfected in our weakness (2 Corinthians 12:9). Faith has clear marks. It runs contrary to human reason and logic (Romans 4:18; Matthew 11:25) and does not depend on sight (Romans 4:18; 2 Corinthians 4:18). It is simply trusting God's Word (Romans 10:17; Galatians 3:16; Hebrews 4:2). It looks impossibility in the face and yet requires no proof (Romans 4:19; Hebrews 11:11). It becomes possible only when we consider ourselves dead—dead to our own strength and resources (Romans 4:19; 6:7-8, 11). It does not waver, refusing to be tossed back and forth (Romans 4:20; James 1:6-8). And it is conviction, not mere profession—not what we say but what we are willing to act on (Romans 4:21; 1 Corinthians 4:19-20). Gideon shows it: still afraid, he acted on God's word and marched against an overwhelming enemy, because the difference between a hero and a coward is not the absence of fear but the refusal to quit. Faith does not give up; it keeps blowing the trumpet and trusting God to break the vessel so the light shines through.