From the Greek apostolos — one sent out on behalf of another. In the NT, applied to those sent by Christ as direct witnesses of his resurrection; the authority is tied to the sending and the witness, not to an institutional title that can be passed down.
An English construction — at-one-ment — coined by Tyndale, not a direct translation. The Hebrew behind it, kaphar, means to cover, sharing its root with kapporeth — the cover of the ark, the mercy seat. The Day of Atonement centers on the High Priest bringing blood to that cover. The act and the object are the same word pointing at…
