I use Bible Hub. It gives a word count. After a bit more research, I found that some translators substituted "Christian" for "believer".
Bible Hub has most of the versions. King James is not the original. The Wycliffe version predates it. Funnily enough, so do the Greek and Hebrew originals.
I've never used the KJV. I use the words Christian/believer/brethren interchangeably myself. Do you think that Peter followed Roman customs? He was a fisherman, not a philosopher.
I don't know what you are trying to prove. Perhaps you could explain it. I'm not a philosopher either. Or a fisherman for that matter.
No, Peter did not follow Roman customs, but his writing reveals what I’m saying.
“Indeed, none of you should suffer as a murderer or thief or wrongdoer, or even as a meddler. But if you suffer as a Christian, do not be ashamed, but glorify God that you bear that name.”
He is writing to believers who know that suffering for Christ is a staple of the gospel. There is no shame in this. Peter redresses the shame for suffering “as a Christian” because that is the label others put upon them. His encouragement was “They associate you with Christ! Glorify God!”
What arose out of this Roman influence, among others, was a systematic, religious system not anything like what we see between Christ and His disciples. And, nothing that fulfills the characteristics of a “holy nation”.