Faith is knowing.
The assured expectation of things not yet seen.
You can have faith in someone... in the sense of trusting someone to do as they have told you; or trusting that what they say is true. But how can you have faith in someone you aren't even sure is real?
Faith is knowing someone not yet seen. Faith hears and obeys. Abraham put his faith in the One he heard... he heard, believed, and obeyed (faith and works).
People don't tend to have faith in someone they do not know, or someone they are not sure even exists. That is why it is knowing Christ, that means life. Not 'taking in knowledge', that means life.
Peace,
tammy