Well, there are different sorts of reason. One could want scientific proof, or rely on strong rationalizing. You're reason may even come from personal experiences that could be considered strong, or weak (miracles for example).
Basically, do you believe its important to know you're right (in some sort of sense), or just believe you are (strong faith).
Of course, in Christianity we're toldin scripture that it takes only faith. But we're also told to be able to defend our faith ( as the apostles did). But by building one, do you lessen the other. They could be seen as two diametrically opposed concepts after all.