However, belief due to evidence means believing that the evidence is true. Well, you can't discount that possibility. In other words, evidence is basically a collection of observations, experiments, and inferences all tied together in a nice, neat, little package. I can also return to why science is usually believed. Science proceeds from the left of my equation, starting with the first.
Philosophy usually follows the same path as well.
However, when people accept something on faith alone , they skip the bottom, and then look only for evidence that supports their belief . And, whether or not they find any, most people are more willing to cling to a belief that has no support than to change to a better supported belief . But what I am saying is that they had no rational reason to believe what they did. Drawing the line between Heart Truth and Belief Ouch. This is one topic I'd rather not delve into, but I feel that it's necessary.