Actually believers are slaves of Christ.
Thayer's Greek Lexicon
STRONGS NT 1401: δοῦλος
δοῦλος, δούλη, δοῦλον (derived by most from δέω, to tie, bind; by some from ΔΑΛΩ, to ensnare, capture ((?) others besides; cf. Vanicek, p. 322)); serving, subject to: παρεστήσατε τά μέλη ὑμῶν δοῦλα τῇ ἀκαθαρσία,
Romans 6:19. Then substantively, ἡ δούλη, a female slave, bondmaid, handmaid: τοῦ Θεοῦ, τοῦ κυρίου, one who worships God and submits to him,
Acts 2:18 (from
Joel 2:29 ());
Luke 1:38, 48. ὁ δοῦλος, the Sept. for עֶבֶד;
1. a slave, bondman, man of servile condition;
a. properly: opposed to ἐλεύθερος,
1 Corinthians 7:21;
1 Corinthians 12:13;
Galatians 3:28;
Ephesians 6:8;
Colossians 3:11;
Revelation 6:15;
Revelation 13:16;
Revelation 19:18; opposed to κύριος, δεσπότης, οἰκοδεσπότης,
Matthew 10:24;
Matthew 13:27;
Luke 12:46;
John 15:15 Ephesians 6:5;
Colossians 3:22;
Colossians 4:1;
1 Timothy 6:1;
Titus 2:9, and very often.
Acts 2:18 N-AMP
GRK: ἐπὶ τοὺς
δούλους μου καὶ
NAS: EVEN ON MY BONDSLAVES, BOTH MEN AND WOMEN, I WILL IN THOSE
KJV: on my servants and on
INT: upon the servants of me and
Acts 4:29 N-DMP
GRK: δὸς τοῖς
δούλοις σου μετὰ
NAS: and grant that Your bond-servants may speak
KJV: grant unto thy servants, that with all
INT: grant to the servants of you with
Acts 16:17 N-NMP
GRK: οἱ ἄνθρωποι
δοῦλοι τοῦ θεοῦ
NAS: men are bond-servants of the Most High
KJV: are the servants of the most high
INT: men servants of the God
Romans 1:1 N-NMS
GRK: ΠΑΥΛΟΣ
δοῦλος Ἰησοῦ Χριστοῦ
NAS: Paul, a bond-servant of Christ Jesus,
KJV: Paul, a servant of Jesus Christ,
INT: Paul servant of Jesus Christ
Romans 6:16 N-AMP
GRK: παριστάνετε ἑαυτοὺς
δούλους εἰς ὑπακοήν
NAS: to someone [as] slaves for obedience,
KJV: ye yield yourselves servants to obey,
INT: you yield yourselves servants for obedience
Romans 6:16 N-NMP
GRK: εἰς ὑπακοήν
δοῦλοί ἐστε ᾧ
NAS: for obedience, you are slaves of the one whom
KJV: to obey, his servants ye are to whom
INT: for obedience servants you are to him whom
Romans 6:17 N-NMP
GRK: ὅτι ἦτε
δοῦλοι τῆς ἁμαρτίας
NAS: be to God that though you were slaves of sin,
KJV: that ye were the servants of sin, but
INT: that you [once] were servants of sin
Romans 6:19 Adj-ANP
GRK: μέλη ὑμῶν
δοῦλα τῇ ἀκαθαρσίᾳ
NAS: your members as slaves to impurity
KJV: members servants to uncleanness
INT: members of you in bondage to uncleanness
Romans 6:19 Adj-ANP
GRK: μέλη ὑμῶν
δοῦλα τῇ δικαιοσύνῃ
NAS: your members as slaves to righteousness,
KJV: members servants to righteousness
INT: members of you in bondage to righteousness
Romans 6:20 N-NMP
GRK: ὅτε γὰρ
δοῦλοι ἦτε τῆς
NAS: For when you were slaves of sin,
KJV: ye were the servants of sin,
INT: when indeed servants you were
1 Corinthians 7:21 N-NMS
GRK: δοῦλος ἐκλήθης μή
NAS: Were you called while a slave? Do not worry
KJV: Art thou called [being] a servant? care
INT: servant [being] were you called not
1 Corinthians 7:22 N-NMS
GRK: κυρίῳ κληθεὶς
δοῦλος ἀπελεύθερος κυρίου
NAS: in the Lord while a slave, is the Lord's
KJV: the Lord, [being] a servant, is
INT: [the] Lord having been called [being] a slave a freedman of [the] Lord
1 Corinthians 7:22 N-NMS
GRK: ἐλεύθερος κληθεὶς
δοῦλός ἐστιν Χριστοῦ
NAS: while free, is Christ's slave.
KJV: is Christ's servant.
INT: free having been called a slave is of Christ