Faith. We all know the word, and we all know it's important, but sometimes we're not sure what it is or if we have it. In Hebrews 11, God gives us a straightforward definition of faith, then illustrates it through the lives of men and women who saw the invisible and lived by faith in what they saw. These were faithful but fallible people who were sometimes victorious and sometimes defeated--just like us. Just like them, we can learn to live by faith in the invisible.