A.T. Robertson Commentary Romans 15:16

"that I should be a minister of Christ Jesus unto the Gentiles, ministering the gospel of God, that the offering up of the Gentiles might be made acceptable, being sanctified by the Holy Spirit." — Romans 15:16 (ASV)

That I should be (εις το εινα με). The εις το idiom with the infinitive again (verses 8,13).

Minister (λειτουργον). Predicate accusative in apposition with με and see 13:6 for the word. "The word here derives from the context the priestly associations which often attach to it in the LXX" (Denney). But this purely metaphorical use does not show that Paul attached a "sacerdotal" character to the ministry.

Ministering (ιερουργουντα). Present active participle of ιερουργεω, late verb from ιερουργος (ιεροσ, εργω), in LXX, Philo, and Josephus, only here in N.T. It means to work in sacred things, to minister as a priest. Paul had as high a conception of his work as a preacher of the gospel as any priest did.

The offering up of the Gentiles (η προσφορα των εθνων). Genitive of apposition, the Gentiles being the offering. They are Paul's offering. See Ac 21:26.

Acceptable (ευπροσδεκτος). See 2 Corinthians 6:2; 8:12. Because "sanctified in the Holy Spirit" (ηγιασμενη εν πνευματ αγιω, perfect passive participle of αγιαζω).