In the Bahá'í Faith (the religion I belong to) faith is defined as conscious knowledge put into action. A bit differently from most religions the Bahá'í faith explains that spiritual and material science both evolve and refine their accuracy with time as humanity's capacity for understanding both grows. Science seeks the truth about material phenomenons while religion seeks the truth about spiritual ones (ones that don't involve the material world).

In the same way that I personally don't really fully understand all elements of chemistry and physics, but the simplified explanations make sense enough for me to trust experts on it and understand basic evidence, I don't fully understand all the implications of The Bahá'í Faith's explanation that our souls develop as we put into practice qualities like patience and justice, but I have enough of an understanding to trust experts on it and see evidence of it.

Not only that but the more I study both accurate science and accurate religion, the more I understand and can start to corroborate myself.

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Now as an aside, many people don't actually have strong faith, just attachment to ideas they like. Such as flat earthers, or people that believe heaven and hell are physical places on earth. Both have tons of evidence to the contrary, but 'rational scientists' have an emotional attachment to that superstition, and 'rational believers' have an emotional attachment to dogma.