With this verse Peter makes use of a proverbial declaration where something is said to be better than something else. Such declarations are quite common in the Bible (Psalm 37:16; Proverbs 3:14; Proverbs 8:11, Proverbs 8:19; Proverbs 15:16–17; Proverbs 16:8, Proverbs 16:19, Proverbs 16:32; Proverbs 17:1; Proverbs 19:1; Proverbs 21:9, Proverbs 21:19; Proverbs 25:7, Proverbs 25:24; Proverbs 27:5; Proverbs 28:6; 1 Corinthians 7:9; 1 Peter 3:17).
The way of righteousness is also referred to elsewhere in Scripture (Matthew 21:32; Job 24:12–13 and Proverbs 21:16, Proverbs 21:21) and most likely refers to knowing Christ/the moral life demanded by those who belong to God.1 Indeed, Christianity was originally known simply as the Way
(Acts 9:2; Acts 19:9).2 Biblically, commandment can refer to Old Testament law (Romans 7:12; Matthew 5:19; Matthew 15:3; Matthew 19:17; Ephesians 6:2; Hebrews 9:19) or to the commandment of Christ (John 13:34; John 14:15, John 14:21; John 15:10, John 15:12; 1 Corinthians 14:37; 2 Peter 3:2; 1 John 2:7–8; 1 John 3:22–24). In this instance it most likely has to do with the substance of the initial teaching that new converts receive, basic teaching of Christ.3
21 For it would have been better for them never to have known the way of righteousness than after knowing it to turn back from the holy commandment delivered to them.