The word faith in general means to believe in something regardless of any proof supporting it. It is the purposeful suspension of the knowledge faculties, and goes completely against the grain of most scientists. But the dual nature of all consciousness teaches us that if we consider knowledge to be a useful tool, then to use it to its fullest we must embrace its diametric compliment - the active use of not-knowledge, i.e. faith.
When faith is used in balance with knowledge, it means that although doubt and scepticism are extremely useful tools, they should be used in the right time rather than continuously. At other times scepticism is not useful, and pure receptivity is best. When the Taoist sage Lao Tzu said that to learn from him you needed an empty cup, he didn't mean that you should be required to trust him any more than anyone else, merely that the time for sceptical investigation of his ideas was best left for after the lessons.