God is the author of joy
What does the Bible say about joy? First, we need to step back and look at how we understand God.
When we think of God, we view Him as many different things—a somber judge, a righteous king, a loving father—but we seldom think of Him as joyful. Yet He is! We know God found joy within His Creation when He declared it good, and we’re told of unspeakable joy in Heaven whenever a sinner comes to know Him.
Even in moments where God must exercise judgment, His joy always prevails since it's intrinsically part of His nature. Psalm 30:5 (NLT) says, “For His anger is but for a moment, His favor is for a lifetime; Weeping may last for the night, but a shout of joy comes in the morning.”
But more than just exhibiting joy, the mere presence of God produces joy because God is our joy. Romans 15:13 (ESV) reveals the secret to receiving this joy: “May the God of hope fill you with all joy and peace in believing, so that by the power of the Holy Spirit you may abound in hope.” God is the supplier of joy, and through the power of the Holy Spirit, we have access.

Joy vs happiness
When we think of joy, it conjures up images of celebration, jubilance, and excitement. We see joy as a synonym for happiness—an emotion brought about by circumstances—but there’s often a disconnect when we think about biblical joy.
God’s joy comes through finding pleasure and contentment through Jesus rather than our circumstances. As Jesus reminds us in John 16:22 (ESV), “So also you have sorrow now, but I will see you again, and your hearts will rejoice, and no one will take your joy from you.” God is our joy, which means our joy doesn’t depend on the world. Our joy can't be taken from us!
Look at the apostles who suffered great persecution, even jailed for extended periods of time, yet they found joy regardless of their circumstances. 1 Peter 1:3-6 speaks of a living hope and inheritance waiting for us in heaven through the resurrection of Christ, and reminds us, “in this you rejoice, though … you have been grieved by various trials.”
We find our joy and rest from God, even if our circumstances aren’t great. Happiness is fleeting, but God’s joy is eternal. It’s a mindset, it’s a lifestyle, and it’s a choice—a choice independent of emotions and life circumstances.

What circumstances call for joy?
Which circumstances do we need to have joy? All of them, and it’s harder than you think! However, it’s imperative to source our joy from God because life doesn’t always provide it. Regardless of what we might be facing, 1 Thessalonians 5:16 (NIV) commands us to “Rejoice always.”
Rejoice when you are blessed
This might sound obvious, but it’s easy to get so wrapped up in the blessing we forget to acknowledge God. As James 1:17 says, all blessings and gifts come from above—from God. When good things come our way, when we’re encouraged, when we’re loved, and when we’re given affection, we’re meant to worship and rejoice.