The noun translated as “faith” is pistis (πίστις), which means means "confidence," "assurance," "trustworthiness," "credit," "a trust," and "that which give confidence." Jesus uses this word twenty-six times, usually in the context of trusting the truth about someone’s words, usually his words. Even Strong’s Biblical Concordance says that it means “conviction of the truth of anything” but Strong’s goes on to say that, in the New Testament (NT), its meaning changed to “a conviction or belief respecting man's relationship to God and divine things.” Since it didn’t mean religious faith before the NT, it couldn't have been heard that way by those listening to Jesus.
The evidence that this word had little to do with religious belief before the NT is overwhelming. In the Greek version of the Old Testament, the Septuagint, the Greek word only appears thirty-two times. Most of those verses are about trusting people, not God or prophets, and many of them are not translated into English as any form of “faith” or “belief.” The Greek word is usually used to translate the Hebrew word, 'ĕmûnâ (אֱמוּנָה)(or a related word), which Strong’s defines as “firmness, fidelity, steadfastness, and steadiness.” This Hebrew word is often translated as “truth” in the KJV.
Whenever Jesus discusses “faith,” we make a mistake by assuming that he means having religious faith. He means simply having confidence in someone, someone’s word, or more generally in survival. For example, Jesus seems to have invented the Greek word, oligopistos (ὀλιγόπιστος) translated as “you with little faith.” That word would have been heard as “little confidence.” He only uses this word six times, but twice he does so in the context of people worrying about having enough food or good clothes to wear.
However, this word becomes much more popular in the writings of the other New Testament authors. They use it two hundred and forty-one times. It meant the same for them as it did for Jesus and his listeners, trusting the truth of something. However, they use it to ask people to trust the truth of what Jesus said and what they said about Jesus. This idea became the basis for the idea of “faith” coming to mean religious faith in modern languages influenced by the NT.