Hart offers, as ever. an interesting note to this verse in his translation of the NT:The only people who are called “Christians” in the Bible are the disciples in Antioch, and it isn’t Jesus or the apostles who are calling them that. It probably means “people who think that Jesus was the Christ.” It doesn’t say anything about what they are saying about Him, other than being a promised king of Israel.
χρηματίσαι τε πρώτως ἐν Ἀντιοχείᾳ τοὺς μαθητὰς Χριστιανούς (chrématisai te protosen Antiocheia; tous mathétas Christianous).
"... It should be noted that there is a certain oddity to the very word Christianos, since it is not a natural Greek nominalisation; rather, it is a Latin nominalisation transliterated into Greek, and Latin was certainly not the common tongue of first-century Antiochenes."
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So yes, it's quite likely the term was coined by people who had no real idea about what they taught, other than they seemed to bang on a lot about repentance and forgiveness and their man Jesus the Annointed.