Philippians 1:10

So that ye may approve the things that are excellent; that ye may be sincere and void of offense unto the day of Christ.

Approve the things which are excellent ... This is very similar to "distinguish things that differ" as Paul wrote in Romans 2:18; and both here and there, "It is impossible to decide exactly what Paul means.[25] One thing is evident, Paul wanted the Philippians to grow in knowledge in order to avoid offense in living the Christian life. Russell thought that Paul's words in Philippians 4:8 show what is meant by "the things which are excellent," as used here.[26]

Sincere ... It has often been pointed out that this word is derived from two Latin words, "sin" (without) and "cere" (wax). Italian marble vendors and certain merchants of porcelain fell into the habit of hiding flaws in their merchandise by filling cracks and blemishes with a certain kind of wax; but the more reputable dealers advertised their wares as sin/cere (without wax); and from this derived the meaning of the English word "sincere." The true meaning of it is "without deception" or "without hypocrisy."

Unto the day of Christ ... This is another reference to the judgment and final advent of Jesus our Lord.

[25] John Murray, The Epistle to the Romans (Grand Rapids, Michigan: Wm. B. Eerdmans Publishing Company, 1968), p. 82.

[26] James William Russell, op. cit., p. 487.