6:5 οἱ δοῦλοι, ὑπακούετε τοῖς κατὰ σάρκα κυρίοις μετὰ φόβου καὶ τρόμου ἐν ἁπλότητι τῆς καρδίας ὑμῶν ὡς τῷ Χριστῷ,
οἱ δοῦλοι – Vocative, defining the subject of the imperative.
ὑπακούετε τοῖς κατὰ σάρκα κυρίοις – Present active imperative. The verb marks its object with the dative case τοῖς κυρίοις. Paul wants to prevent any confusion about which κύριος is involved and so he adds κατὰ σάρκα which indicates the standard which defines these masters or owners. Presumably this category contrasts with ὁ κύριος ἐν οὐρανοῖς identified in v.9.
μετὰ φόβου καὶ τρόμου – An adverbial prepositional phrase in which μετά + genitive indiciates attendant circumstances, often of moods, associated with an action. The two nouns may indicate respect, as well as convey some element of “fear,” given the legal authority a master possessed.
ἐν ἁπλότητι τῆς καρδίας ὑμῶν – This adverbial prepositional phrase indicates the manner in which the Christians will show obedience. The noun refers to an essential simplicity of motive that is focused on one factor and thus points to integrity. The genitive τῆς καρδίας is probably subjective, but might indicate source, with ὑμῶν indicating possession.
ὡς τῷ Χριστῷ — This comparative clause implies the imperative ὑπακούετε and so the dative marks the indirect object of the implied verb. Here τῷ Χριστῷ would have a titular sense.
6:6 μὴ κατ’ ὀφθαλμοδουλίαν ὡς ἁνθρωπάρεσκοι ἀλλ’ ὡς δοῦλοι Χριστοῦ ποιοῦντες τὸ θέλημα τοῦ θεοῦ ἐκ ψυχῆς,
μὴ κατ’ ὀφθαλμοδουλίαν – Paul seems to continue with an implied ὑπακούετε, with the adverbial prepositional phrase indicating the standard of obedience which is to be rejected, i.e., a kind of service that only acts appropriately when the master is present, or perhaps only acts in ways designed to curry favour.
ὡς ἁνθρωπάρεσκοι – In this comparative clause the adjective functions substantively as the subject of the implied verb ὑπάκουσι.
ἀλλ’ ὡς δοῦλοι Χριστοῦ — ἀλλ’ is adversative and indicates what behaviour should replace that negated in the previous clause. δοῦλοι is the subject of an implied ὑπάκουσι. It is modified by a genitive of possession or subordination.
ποιοῦντες τὸ θέλημα τοῦ θεοῦ ἐκ ψυχῆς – The present active participle could be attributive, qualifying these δοῦλοι, or it could be adverbial, related to the implied ὑπάκουσι and indicating time or means. It is modified by a direct object in the accusative case. τοῦ θεοῦ is probably a subjective genitive, i.e., it is God that is willing this. ἐκ ψυχῆς problem defines the source of the motivation to do this will.
6:7 μετ’ εὐνοίας δουλεύοντες ὡς τῷ κυρίῳ καὶ οὐκ ἀνθρώποις,
μετ’ εὐνοίας δουλεύοντες – It is unclear whether this adverbial present active participle gives additional information for the previous δοῦλοι Χριστοῦ (v.6) or the initial οἱ δοῦλοι (v.5). It could be causal or purpose. If it is parallel with ποιοῦντες (v.6), then it could also be attributive. The adverbial prepositional phrase indicates that manner in which they perform their slaved duties, i.e., with a good attitude, benevolence
ὡς τῷ κυρίῳ καὶ οὐκ ἀνθρώποις – Two more comparative clauses coordinated by καί. The implied verb is probably δουλεύω which takes a dative complement.
6:8 εἰδότες ὅτι ἕκαστος ἐὰν τι ποιήσῃ ἀγαθόν, τοῦτο κομίσεται παρὰ κύριου εἴτε δοῦλος εἴτε ἐλεύθερος.
εἰδότες – This perfect active participle functions adverbial in a causal way to add explanation to the initial command in v.5.
ὅτι ἕκαστος — ὅτι marks the indirect discourse clause which functions as the object of εἰδότες. Within the indirect discourse ἕκαστος is the subject of κομίσεται.
ἐὰν τι ποιήσῃ ἀγαθόν – A third class conditional clause in which the contingency is probably temporal. τι is the direct object and ἀγαθόν is adjectival modifier in a predicate position. ποιήσῃ may pick the previous participle ποιοῦντες.
τοῦτο κομίσεται παρὰ κύριου – τοῦτο is the object of κομίσεται, a future indicative middle tense form meaning “receive a recompence.” The subject is expressed in the following εἴτε…εἴτε structure. The prepositional phrase defines the source of the recompence.
εἴτε δοῦλος εἴτε ἐλεύθερος – Two disjunctive conditional clauses, e.g., “if…if,” but expressing a general idea. The nouns function as predicate nominatives with an implied form of εἰμί.
6:9 Καὶ οἱ κύριοι, τὰ αὐτὰ ποιεῖτε πρὸς αὐτούς, ἀνιέντες τὴν ἀπειλήν, εἰδότες ὅτι καὶ αὐτῶν καὶ ὑμῶν ὁ κύριος ἐστιν ἐν οὐρανοῖς καὶ προσωπολημψία οὐκ ἔστιν παρ’ αὐτῷ.
Καὶ οἱ κύριοι – Paul shifts attention to a new group, using the vocative οἱ κύριοι to identify the subject of the imperative.
τὰ αὐτὰ ποιεῖτε πρὸς αὐτούς – The present active imperative takes an accusative direct object which is placed before the verb for prominence. αὐτά is neuter accusative plural and means “the same things.” The adverbial prepositional phrase indicates the targeted group, i.e., δοῦλοι.
ἀνιέντες τὴν ἀπειλήν – Adverbial present active participle from the verb ἀνίημι, which means “abandoning, giving up.” It is probably temporal (“giving up….), but could also be causal or define manner. ἀπειλή means “threat” and is the object of the participle.
εἰδότες – A perfect active participle which gives the explanation for the action required in the imperative.
ὅτι καὶ αὐτῶν καὶ ὑμῶν ὁ κύριος ἐστιν ἐν οὐρανοῖς — ὅτι marks the following clause as indirect discourse and it functions as the object of the participle. An equative clause forms the discourse and the subject is indicated by the article. The adverbial prepositional phrase has a spatial sense. The subject is modified by the καὶ αὐτῶν καὶ ὑμῶν, which are both genitives of subordination. The repeated καί is a “both…and” structure. Its placement before the noun is unusual and at the beginning of the clause is even more unusual, indicating its prominence in the mind of the writer.
καὶ προσωπολημψία οὐκ ἔστιν παρ’ αὐτῷ — A second equative clause is coordinated with the first clause in the indirect discourse. The subject probably is προσωπολημψία. The negative indicates that this quality or condition does not exist “with him” – an adverbial prepositional phrase that indicates association.