Don

gengwall,

In Greek the presence of the definite article makes the noun definite, but the absence of the definite article does NOT necessarily make the noun indefinite, see Wallace “Greek Grammar Beyond the Basics”. There is no indefinite article in Koine Greek, so there are 3 basic possibilities when the definite article is not used:
1. The noun is definite, even tho the article is not used to mandate this.
2. The noun is indefinite.
3. The noun is describing a group, of 1 or more that meet the quality.

The decision about which is the best fit is decided by context and there can be disagreement among scholars in some cases.