What Does Romans 6:10 Mean?

For in that he died, he died unto sin once—ho gar apethanen tē hamartia apethanen ephapax (ὃ γὰρ ἀπέθανεν τῇ ἁμαρτίᾳ ἀπέθανεν ἐφάπαξ). Ephapax (ἐφάπαξ, "once for all") emphasizes the unrepeatable, final nature of Christ's atoning death—contra-medieval Mass theology that re-presented the sacrifice. He died unto sin (tē hamartia, dative) can mean "with respect to sin" or "for sin"—Christ died to deal with sin definitively. This isn't Christ dying to His own sin (He had none) but dying to sin's claims against humanity as the sin-bearer (2 Corinthians 5:21).

But in that he liveth, he liveth unto God (ho de zē, zē tō theō, ὃ δὲ ζῇ, ζῇ τῷ θεῷ)—the present tense zē (lives) indicates ongoing resurrection life. Christ's resurrection life is wholly oriented toward God, uninterrupted by death or sin. The parallelism is instructive: Christ's death was to sin (to deal with it finally); His life is to God (in unbroken fellowship). Believers, united to Christ, share this same pattern: death to sin, life to God. The ethical implication is clear: those who died with Christ should live as He lives—oriented wholly toward God.