What does Proverbs 3:2 mean?

This promises that remembering Solomon's teaching and obeying his commandments from the heart will bring his student longevity and peace. Although living to old age is not guaranteed for all Christians, the believer who avoids the harmful effects of sinful habits is far more likely to enjoy a long life along with peace of heart and mind (John 14:27; Ephesians 4:17–24). This is in keeping with the concept of a "proverb," which are general statements of wisdom, not absolute prophecies.

Within the Ten Commandments God gave to Israel was a promise of longevity to those who honor their father and mother (Exodus 20:12). This promise is repeated in Ephesians 6:1–3. Furthermore, obeying God's Word is the best way to avoid a troubled conscience. When King David, Solomon's father, violated the commandment, "You shall not commit adultery" (Exodus 20:14), his guilty conscience made him feel like his bones were broken as he groaned under the weight of sin (Psalm 32:3). With forgiveness and a clear conscience he wrote "Great peace have those who love your law; nothing can make them stumble" (Psalm 119:165).