Faith just means believing something despite having no good evidence for it, or even against the evidence. That is intellectually irresponsible no matter what you're applying it to.

Why people find it persuasive

The everyday, and even some religious, use of the word 'faith' often does describe believing propositions on authority or tradition rather than argument, and there are real communities that treat evidence-seeking as a sign of weak faith. Richard Dawkins has memorably defined faith as 'blind trust, in the absence of evidence, even in the teeth of evidence,' and plenty of believers reinforce that picture by discouraging critical questions.

Important distinctions

• • Faith as fideistic belief against evidence vs. faith as trust grounded in evidence (Greek pistis)
• • Propositional belief vs. relational trust/commitment
• • Popular rhetorical use of 'faith' vs. technical theological/philosophical usage
• • Faith that forecloses inquiry vs. faith that is held while continuing to inquire

Christian response

• • The biblical and classical theological vocabulary for faith, pistis in Greek and emunah in Hebrew, denotes trust and fidelity, closer to the trust one places in a tested friend than to believing an unsupported claim. Hebrews 11:1 defines faith as 'the assurance of things hoped for, the conviction of things not seen,' which is not a claim about absence of evidence but about confidence extending beyond what is presently visible, in the same way trusting a friend's character extends beyond watching them every second.
• • Major Christian thinkers across history explicitly rejected evidence-free belief. Thomas Aquinas built natural theology on rational argument before addressing revealed doctrine; Anselm's phrase 'fides quaerens intellectum,' faith seeking understanding, describes faith as the starting point for inquiry, not the substitute for it. Contemporary philosophers of religion such as Richard Swinburne and Alvin Plantinga defend theism using cumulative case arguments and epistemology, not appeals to blind assertion.
• • Everyday life runs on trust that outruns exhaustive proof in exactly the same structural way. You trust a spouse's fidelity, a friend's honesty, or a scientific theory's future predictions based on a track record and inference to the best explanation, not because you have logically certain proof; this kind of warranted trust-beyond-certainty is what mature religious faith claims to be, not an epistemic blank check.
• • It is fair to concede that faith is sometimes preached and practiced badly, as an anti-intellectual refusal to engage doubt or evidence, and this deserves criticism rather than a hasty defense. But the existence of bad instances of a concept does not refute the concept itself; bad science does not refute science, and fideistic faith does not establish that faith as such must be evidence-free. The proper target of the objection is fideism, a real but minority position, not faith per se.

Christian counterresponse

The theist can note that the same is true of belief in evolution, historical facts, or the reliability of one's senses among ordinary non-specialists, so a gap between expert justification and lay appropriation is not unique to religion and does not show the underlying position is unjustified.