Using faith to establish truth or to claim knowledge is risky because faith means belief without evidence. It is an unreliable process that will not lead to the truth. It is pretending to know something you don’t know. If you have evidence, you don’t need faith.
We should not use the word “faith” to mean hope, trust or confidence, as in “I have faith (hope) you will keep your promise.” “I have faith (confidence) the bus will stop here.” Reasonable hope, trust and confidence are based on experience. I have experience with you as a reliable person or I trust my judgment of your character. My experience tells me the bus stops here every day or that the posted bus schedule is accurate. These are not claims of knowledge or truth about the world. To hope something happens acknowledges the possibility it may not happen. Christians who claim to know by faith that Jesus walked on water do not mean they hope he walked on water.
Admitting uncertainty or ambiguity is preferable to believing something for which no evidence is available or possible. Determination or persistence in the face of uncertainty and ambiguity can be very useful and can help us persist in difficult endeavors while striving. But maintaining a belief that contradicts reason or well-established facts is delusional. Knowing the difference between determination and delusion requires open-minded inquiry and reasoning. Subjective experiences and beliefs are not enough to assert verifiable knowledge.
When a story that was meant to be a metaphor is taken literally, the meaning is completely distorted to the point of being absurd. The Aesop Fable of the ant and grasshopper teaches us to prepare for the future. It’s not necessary to believe an ant and a grasshopper actually talked to each other, and it would be a serious mistake to think that all grasshoppers are doomed because they don’t store food for the winter. Grasshoppers have not become extinct in spite of the metaphorical truth of the fable. The Aesop Fable is not meant to describe the science of how grasshoppers survive winter.
Biblical literalists make a similar mistake when, for example, they argue that the Genesis myth is equivalent to science. Questioning the details, such as whether the “day” described in Genesis is 24 hours or some other time period, misses the point. More appropriate questions are: What was the writer trying to convey? Who was the intended audience? What was the writer’s culture? Does this myth still have relevance to modern people? Biblical scholars have wrestled with these questions, and most Christian clergy who are trained in reputable seminaries have this knowledge. Some are reluctant to preach it because they fear people will be distressed if their childhood beliefs are challenged.
When faith is used to assert knowledge or is claimed to be superior to evidence or denies or contradicts reason, it becomes delusional and leads away from ultimate truth. As Valerie Tarico says in The Dark Side: How Evangelical Teachings Corrupt Love and Truth, “I would rather live with unanswered questions than unquestioned answers.”
Faith is unreliable and leads to potentially dangerous beliefs. Faith may bring personal emotional comfort, but not truth. Truth must be built on reason and evidence. Any belief that cannot be tested or cannot stand up to reason cannot be truth. Criticizing an idea or cultural practice or action or religious text is always justified. Harming or killing those who disagree with us is reprehensible and intolerable.