Words are more interesting than any puzzle. Sometimes the history of a word opens up a window on the habits and customs of a past generation. The common english word “butcher,” for example, takes us  back through the French “boucher,” when “bouc” or goat meat was the chief meat on the diet.

Few words, however, have a more interesting lineage than the word “sincere.” Among the theories advanced to explain this word is the one that sees its derivation from “sine”—without, and “cera”—wax. In the ancient Roman world a sculptor sometimes chipped off too large a piece from the marble. Rather than begin his work over again, he used wax to fasten the piece back onto the image. This would stand the temporary test and the sale would be made, but soon the fraud would show up. It became necessary, in drawing up contracts with sculptors, to insert the word “sinecera”—without wax.

The Greek word used in the classics and in the New Testament to express the idea of sincerity comes from the word meaning “sunlight” and to “unfold.” When a product was examined in the clear light of the sun and found to be pure and unsullied, it was “sincere.”

In the light of these meanings, what vigor is to be found in Paul’s prayer for the Philippians. “That ye may approve things that are excellent, that ye may be sincere and without offence till the day of Jesus Christ”—that ye may be without fraud, unfolded in the sunlight.

The natural man loves darkness rather than light—loves his own opinions rather than God’s revelation (John 3:19). David Nelson indicated, a century ago, that one small, cunningly-devised falsehood will influence the natural man more than one hundred plain and forcible arguments in favor of revelation. It is when a man is born again that he loves light and truth rather than darkness, and can live in a sincere way, that is, without fraud, and unfolded in God’s sunlight. (Donald Grey Barnhouse)

Source: Timeless Illustrations for Preaching and Teaching by Donald Grey Barnhouse, 406.