All human knowledge and reason can be seen as dependent on faith: faith in our senses, faith in our reason, faith in our memories, and faith in the accounts of events we receive from others. Accordingly, faith can be seen as essential to and inseparable from rationality. According to Rene Descartes, rationality is built first upon the realization of the absolute truth "I think therefore I am," which requires no faith. All other rationalizations are built outward from this realization, and are subject to falsification at any time with the arrival of new evidence.
When you hear a news story from another country, or of an event that you did not personally witness, do you take it at face value as an absolute fact, or do you need some degree of faith in order to believe that the account of the event actually happened and is true? And even if you did witness an event, do you not require some degree of faith in your own senses and memory in order to form an account of the event?
For example, how does one person arrive at the conclusion that Jesus, as a historical figure, did not exist - yet Socrates did?