2:17-24 The apostle directs his discourse to the Jews, and shows of what sins they were guilty, notwithstanding their profession and vain pretensions. A believing, humble, thankful glorying in God, is the root and sum of all religion. But proud, vain-glorious boasting in God, and in the outward profession of his name, is the root and sum of all hypocrisy. Spiritual pride is the most dangerous of all kinds of pride. A great evil of the sins professors is, the dishonour done to God and religion, by their not living according to their profession. Many despise their more ignorant neighbours who rest in a dead form of godliness; yet themselves trust in a form of knowledge, equally void of life and power, while some glory in the gospel, whose unholy lives dishonour God, and cause his name to be blasphemed.
18. approvest the things that are excellent—"triest the things that differ" (Margin). Both senses are good, and indeed the former is but the result of the latter action. (See on Php 1:10).