the rest: the remaining part of a group once part of it has already been named or set apart
This word always points back to a group that has already been split in the speaker's mind. Someone or something has been singled out, and this word gathers up everyone or everything left over: the others, the remainder, what is still to come. It does no more than that, so its color comes entirely from what it is left over from. With people it means the rest of the crowd, the other apostles, the others who do not yet believe. With things it means the other desires, the remaining matters, the rest of the churches.
The two senses below are the same idea seen from two angles. Sometimes the word stands on its own as a noun and simply names a leftover group of people, the others. Sometimes it leans on a noun it is describing and means the remaining or the other ones of that kind. Greek lets a writer drop the noun when it is obvious, so the line between the two can be thin, but the shared core never changes: this is the part of a set that is not the part already in view.
Because it is a pointer rather than a label, it carries no built-in praise or blame. Whether the rest are godly or hostile, saved or lost, depends wholly on the sentence around it. In a few New Testament passages that surrounding context gives the word real weight, as when Paul writes that believers should not grieve like the rest who have no hope, or when Revelation speaks of the rest of humanity who would not repent.