Let the heavens rejoice, and let the earth be glad; let the sea roar, and all its fullness; let the field be joyful, and all that is in it. Then all the trees of the woods will rejoice before the Lord.—Psalm 96:11–12

Sing, O heavens! Be joyful, O earth! And break out in singing, O mountains!—Isaiah 49:13

The deepest happiness comes from being personally connected with God.

In Your presence is fullness of joy; at Your right hand are pleasures forevermore.—Psalm 16:11

Let all those who seek You rejoice and be glad in You.—Psalm 40:16

Happy are the people whose God is the Lord!—Psalm 144:15

“These things I [Jesus] have spoken to you, that My joy may remain in you, and that your joy may be full.”—John 15:11

Faith in God’s goodness engenders happiness.

Happy is he … whose hope is in the Lord his God.—Psalm 146:5

Whom having not seen you love. Though now you do not see Him, yet believing, you rejoice with joy inexpressible and full of glory.—1 Peter 1:8

Even in hard times, God can give us joy.

[God’s] favor is for life; weeping may endure for a night, but joy comes in the morning.—Psalm 30:5

Though the fig tree may not blossom, nor fruit be on the vines; though the labor of the olive may fail, and the fields yield no food; though the flock may be cut off from the fold, and there be no herd in the stalls—yet I will rejoice in the Lord.—Habakkuk 3:17–18

We can always be happy for salvation.

I will greatly rejoice in the Lord, my soul shall be joyful in my God; for He has clothed me with the garments of salvation.—Isaiah 61:10