I received the following comments:
A Word Study on the Salvation of Acts 28:28
Salvation in Greek takes three forms. The following is taken from A Concise Greek-English Dictionary of the New Testament by Barclay M Newman Jr.
Soteria is a feminine noun meaning salvation, deliverance, preservation or release.
Soterion is a neuter noun meaning salvation or saving power
Soterios or Soterion is an adjective meaning bringing salvation
The following is from the Greek English Concordance to the New Testament by Kohlenberger, Goodrick and Swanson.
Soteria occurs over 44 times in the New Testament.
Soterion occurs 4 times in the New Testament.
Luke 2:30 For my eyes have seen Your salvation
Luke 3:6 And all mankind will see God’s salvation
Acts 28:28 God’s salvation has been sent to the nations
Eph 6:17 Take the helmet of salvation
Soterios occurs only once in the New Testament.
Tit 2:11 the grace of God that brings salvation
Soterion is an adjective, not a noun. Claiming it is a noun is an attempt to redefine it. The Greek noun for salvation is “soteria,” and is feminine.
Soterion actually occurs quite often in the Greek Septuagint, which of course is not inspired. It is used forty-one times where the word “salvation” appears in our English Bibles (I was unable to find a search engine to check the Greek occurrences in the Septuagint that may not be translated as “salvation.”) It appears in different forms, which points to the fact of it being an adjective, but it seems to often form an ellipsis, that is, with no noun attached to it. There are occurrences where it clearly forms an adjective modifying a noun in context.
There is really no difference between soterios and soterion. It is just two different forms of the word, based on where the word is used in the sentence.
This last occurrence is clearly an adjective, and would better read “the salvation-bringing grace of God.”
It is an interesting thing to study.