'Unfruitful' in the Bible

I will rebuke the devourer for you; it will not destroy the fruit of your soil; your vine in the field will not be unfruitful," says Yahweh of hosts.

And do not participate in the unfruitful deeds of darkness, but rather even expose [them].

But also our [people] must learn to engage in good deeds for necessary needs, so that they will not be unfruitful.