Is it ensure, insure, or assure?
late 12c., "Matthew, Mark, Luke or John," from Old French evangelist and directly from Late Latin evangelista, from Greek euangelistes "preacher of the gospel," literally "bringer of good news," from euangelizesthai "bring good news," from eu- "good" (see eu-) + angellein "announce," from angelos "messenger" (see angel).
In early Greek Christian texts, the word was used of the four supposed authors of the narrative gospels. Meaning "itinerant preacher" was another early Church usage, revived in Middle English (late 14c.). Classical Greek euangelion meant "the reward of good tidings;" sense transferred in Christian use to the glad tidings themselves. In Late Latin, Greek eu- regularly was consonantized to ev- before vowels.
a "publisher of glad tidings;" a missionary preacher of the gospel (Eph. 4:11). This title is applied to Philip (Acts 21:8), who appears to have gone from city to city preaching the word (8:4, 40). Judging from the case of Philip, evangelists had neither the authority of an apostle, nor the gift of prophecy, nor the responsibility of pastoral supervision over a portion of the flock. They were itinerant preachers, having it as their special function to carry the gospel to places where it was previously unknown. The writers of the four Gospels are known as the Evangelists.