'Unbelievers' in the Bible

the master of that slave will come on a day when he does not expect him and at an hour he does not know, and will cut him in pieces, and assign him a place with the unbelievers.

but brother goes to law with brother, and that before unbelievers?

If one of the unbelievers invites you and you want to go, eat anything that is set before you without asking questions for conscience’ sake.

So then tongues are for a sign, not to those who believe but to unbelievers; but prophecy is for a sign, not to unbelievers but to those who believe.

Therefore if the whole church assembles together and all speak in tongues, and ungifted men or unbelievers enter, will they not say that you are mad?

Do not be bound together with unbelievers; for what partnership have righteousness and lawlessness, or what fellowship has light with darkness?