The salvation spoken of by Peter at 1 Pet.1;5 is the same salvation spoken of in the following verse by Paul;
"And that, knowing the time, that now it is high time to awake out of sleep: for now is our salvation nearer than when we believed" (Ro.3;11).
this salvation is speaking of the time when christiasn will put on immortal bodies like the body of the lord Jesus ( Phil.3;21).
The "good news" of Christ that was first preached to the Jews concerns the Lord Jesus' identity.
He told the Jews the following:
"And he said unto them, Ye are from beneath; I am from above: ye are of this world; I am not of this world. I said therefore unto you, that ye shall die in your sins: for if ye believe not that I am he, ye shall die in your sins" (Jn.8:23-240.
The Jews should have believed that he is the Son of God and the Christ. and the Jews who believed that truth were saved and given new life and saved the moment they believed. John wrote:
"And many other signs truly did Jesus in the presence of his disciples, which are not written in this book:. But these are written, that ye might believe that Jesus is the Christ, the Son of God; and that believing ye might have life through his name" (Jn.20:30[310.
The Lord Jesus also said the following to those Jews:
"“I tell you the truth, anyone who believes has eternal life" (Jn.6:47).