Paul, a servant of Christ Jesus, called to be an apostle and set apart for the gospel of God—
The Greek word δοῦλος, translated “servant” in some English translations, might be better translated “slave,” though slavery in modern times is not exactly equivalent to slavery in biblical times, at least there’s a general difference. Bill Mounce has a helpful definition:
In the NT a person owned as a possession for various lengths of times (Hebrew slaves no more than seven years, Gentile slaves without time limit), of lower social status than free persons or masters; slaves could earn or purchase their freedom
A male slave, or servant, of various degrees, Mt. 8:9, et al. freq.; a servitor, person of mean condition, Phil. 2:7; fem. δούλη, a female slave; a handmaiden, Lk. 1:38, 48; Acts 2:18; δοῦλος, used figuratively, in a bad sense, one involved in moral or spiritual thraldom, Jn. 8:34; Rom. 6:17, 20; 1 Cor. 7:23; 2 Pet. 2:19; in a good sense, a devoted servant or minister, Acts 16:17; Rom. 1:1; one pledged or bound to serve, 1 Cor. 7:22; 2 Cor. 4:5
We of course were bought by Christ’s blood on the cross, redeemed from slavery to sin and unrighteousness to be slaves to God and to righteousness. We find freedom in this slavery from what once bound us so that we can live according to God’s will, and not our own. But this is never coercive, which might explain in part why it is often translated “servant.” There is a perfect freedom in this. Either way actually, we’re doing what we want to do. As slaves to sin (Romans 6), we want to sin, but find that it is enslaving and debilitating, indeed self-destructive. But as servants/slaves of Christ, we’re finding our way into what God intended for us in the first place. And in that we find rest, peace and contentment. But on this side, and especially given our tendency to drift back, it often feels difficult and confining. To be a slave of Christ ends up meaning that we do what Christ did, take the way of the cross and follow. In so doing we end up denying ourselves and doing what left to ourselves we would never do, at least not with the same motive and heart attitude. In and through Jesus.