15 But the free gift [τὸ χάρισμα] is not like the trespass.
For if many died through one man’s trespass, much more have the grace [ἡ χάρις] of God
and the free gift [ἡ δωρεὰ] by the grace [χάριτι] of that one man Jesus Christ abounded for many.
The Greek word for grace is G5485 χάρις (charis).
χάρισμα is G5486 charisma, or grace-gift.
G1431 δωρεά dórea is a (generic) free gift. By generic, I mean not specifically dependent on χάρις.
This verse equates grace-gift and free gift in grace:
τὸ χάρισμα = ἡ δωρεὰ ἐν χάριτι
In this verse, Paul was just saying the same thing with different words for emphasis.
16 And the free gift [τὸ δώρημα] is not like the result of that one man’s sin. For the judgment following one trespass brought condemnation, but [δὲ] the free gift [τὸ χάρισμα] following many trespasses brought justification.
G1434 δώρημα dóréma comes from verb
G1433 δωρέομαι dóreomai meaning to bestow which comes from
G1325 dídōmi to give and G1431 (dórea genericfree gift).
So, δώρημα is a noun meaning a bestowed (generic) free gift.
Both δωρεά and δώρημα mean genericfree gift. The latter carries an extra sense of endowment.
This verse equates grace-gift with the gift of endowment:
τὸ χάρισμα = τὸ δώρημα
17 For if, because of one man’s trespass, death reigned through that one man, much more will those who receive the abundance of grace [τῆς χάριτος] and the free gift of righteousness [τῆς δωρεᾶς τῆς δικαιοσύνης] reign in life through the one man Jesus Christ.
This verse associates the generic free gift as free gift of righteousness based on grace:
τῆς δωρεᾶς τῆς δικαιοσύνης
Why does Paul use three different words for gift besides grace in Rom. 5:15-17?
There are 3 words for gift:
- δωρεά is a generic free gift.
- δώρημα is a bestowed generic free gift.
- χάρισμα is a special Grace-dependent free gift.
Each word has its nuance. Together, they are very expressive.
Is Paul only using these words as synonyms to reduce repetition of the same word?
The individual words are not synonyms. Dave's answer is correct :) Paul used them to make equations and associations to grace and righteousness.
Is there significance in the different words?
Yes, it makes the passage richer and more expressive—as Dave put it: to ‘drive’ the point ‘home’ :)
Unfortunately, the English translations can't do them full justice :(