Adjectives refer to nouns in two ways: either as an attribute or as a predicate.
The attributive use of the adjective qualifies the noun, to describe, without any assertion about it. The attributive is an adherent description.
The Position: ὀ πίστος δοῦλος or ὀ δοῦλος ὀ πίστος
Note: the adjective comes immediately after the article.
The predicate use of the adjective makes an assertion about the noun. The predicate is an additional statement.
The Position: ὀ δοῦλος πίστος or πίστος ὀ δοῦλος
Note: The adjective does not come immediately after the article but either precedes the article or follows the noun.