Faith is a non-rational belief in some proposition.
A non-rational belief is one which is contrary to the sum of evidence for that belief. A belief is contrary to the sum of evidence for a belief if there is overwhelming evidence against the belief, e.g., that the earth is flat, hollow or is the center of the universe. A belief is also contrary to the sum of evidence if the evidence seems equal both for and against the belief, yet one commits to one of two or more equally supported propositions. The error or deception here is to imply that anything that is not a scientific statement, i.e., one supported by evidence marshaled forth the way scientists do in support of their scientific claims, is a matter of faith. To use 'faith' in such a broad way is to strip it of any theological significance the term might otherwise have.