My high school trigonometry book was the size and heft of two bricks placed side-by-side. I can still see its cover—cherry red with black lettering. I probably damaged my posture by hunching over that textbook for hours at a time—reviewing concepts late into the night. Still, I struggled to understand trigonometry’s sliced-up circles, cosines, and square roots.

Spiritually speaking, there’s another concept I find difficult to grasp: joy. My Bible dictionary says that joy is a quality—not just an emotion—derived from God, which characterizes a Christian’s life. Nice definition, but we need to know how to apply this information.

David experienced joy as he praised God for His blessings. The shepherd boy turned king “shout[ed] with joy” (Psalm 21:1) because God had granted him His heart’s desire. David’s blessings included success, prosperity, rescue from death, a leadership position, long life, and access to God’s unfailing love (Psalm 21:3-7). David rejoiced in the success and victory that God had given him—success that came about because he trusted in God (Psalm 21:7).

Maybe you’re thinking, Of course David was joyful— look at everything God furnished for him! Israel’s king, however, also endured intense heartache, defeat, and fear. David failed at fatherhood (1 Kings 1:6), fled from assassins (1 Samuel 19:18), messed up morally (2 Samuel 11:2-4), and lost an infant (2 Samuel 12:19). Through it all, his relationship with God enabled him to have joy. He testified, “Those who look to [God] for help will be radiant with joy” (Psalm 34:5).

God provides many other sources of joy for believers: His presence (Psalm 21:6), forgiveness for sin (Psalm 32:1-2), His Word (Jeremiah 15:16), and answered prayer (John 16:24). These features of our faith allow us to learn about joy during difficulty, as well as during life’s mountaintop moments.

NLT 365-day reading plan passage for today: Judges 16:22-31