'Unbelieving' in the Bible

but the unbelieving Jews [who rejected Jesus as Messiah] stirred up and embittered the minds of the Gentiles against the believers.

But the [unbelieving] Jews became jealous, and taking along some thugs from [the lowlifes in] the market place, they formed a mob and set the city in an uproar; and then attacking Jason’s house tried to bring Paul and Silas out to the people.

But when some were becoming hardened and disobedient [to the word of God], discrediting and speaking evil of the Way (Jesus, Christianity) before the congregation, Paul left them, taking the disciples with him, and went on holding daily discussions in the lecture hall of Tyrannus [instead of in the synagogue].