When someone tells you they have no faith they are apt to be making a mistake. They may only mean that they think they do not take on faith the same things that you do. Such confessions, or challenges as the case may be, betray, at the very least, that the person believes [for how can they be sure]that speaking to you is necessary or may be helpful to you, themselves or both. Faith is the same concept in many different contexts: whether it is the unquestioning acceptance of impossible and supernatural phenomena and miracles, or trusting readings taken from a thermometer and inferential steps taken to arrive at a mathematical proof...all these are simply things we do in our personal category of "if I had to question that, my world would be meaningless and mad". The resolute reductionist and the person happy to tell grownups and strangers that angels surely watch over their every minute both operate on faith but the former consciously works to minimize what is taken on faith where the latter trusts that even logic itself may be dispensed with. The reductionist is, if thorough and honest in application of their understanding, receptive to argument and evidence but skeptical while the person who has latched on to a comforatable fairy tale becomes resistant and threatened and will go through outlandish intellectual contortions to maintain some sense of the wholeness of their story which wholeness eventually becomes their sole yardstick to measure the value of all evidence and argument. Yet, different and opposed as two such constructions of existance may be, you can see faith at work in both.
If someone says to you "I have no faith", ask them "Then why are you talking to me?"