Faith, or Emunah, is not what society commonly refers to as belief in G-d. Knowing that there is a G-d above does not mean that one has faith. In fact, today, it is quite common for one spouse to believe, while their partner is atheistic. This is because no one expects belief in G-d to impact on one's consciousness or interests. In other words, I may believe in a higher entity somewhere up there, and you may think that life is a black hole.
True faith is something more.
If a trustworthy man asks to borrow a huge amount of money, I would be willing to place all my savings in his hand, confident that he is good for his word. If the borrower is not as reliable, I will hesitate and ask for reassurance, lacking faith in his promise to repay. I promised that I would do so, and she went to sleep quite happily, fully certain that when she awoke the next morning her treasured cereal would be waiting. To her, a father's word is as good as done. This is faith.