'Unfaithful' in the Bible

But the unfaithful heirs of that kingdom will be thrown into the darkness outside. In that place there will be wailing and gnashing of teeth."

the master of that servant will come on a day when he doesn't expect him and at an hour that he doesn't know. Then his master will punish him severely and assign him a place with unfaithful people.

What if some of the Jews were unfaithful? Their unfaithfulness cannot cancel God's faithfulness, can it?

But people who are cowardly, unfaithful, detestable, murderers, sexually immoral, sorcerers, idolaters, and all liars will find themselves in the lake that burns with fire and sulfur. This is the second death."