James 3:13–18 teaches that real wisdom isn’t about knowledge but about living rightly. Earthly wisdom is selfish and leads to envy, disorder, and bitterness, while wisdom from above is pure, peaceful, gentle, and sincere. True wisdom shows in our conduct and humility, producing peace instead of conflict. When we let go of bitterness and trust God, we reap a harvest of righteousness and choose to become better, not bitter.