“Thou hast put gladness in my heart, more than in the time that their corn and their wine increase” ((Psalm 4:7))

What a wonderful thought! David was in the midst of attacks from his enemies, they were turning his glory into shame. So what did he do? He turned to the Lord. And God put gladness in his heart.
Gladness means joy or mirth. The Lord had filled David’s heart with greater joy. Where did this joy of the Lord come from? In the previous verse, David speaks of the light of God’s countenance (literally face). God’s face speaks of God’s presence. When David went into the presence of God, his Lord filed his heart with gladness. And this gladness was greater than his circumstances.
So today, when I face trials, when I am oppressed, when I am depressed, or when I am discouraged, I need to go into the presence of my God, and allow Him to fill my heart with His gladness and greater joy. Then I can find as Nehemiah wrote,

“Then he said to them, ‘Go, eat of the fat, drink of the sweet, and send portions to him who has nothing prepared; for this day is holy to our Lord. Do not be grieved, for the joy of the Lord is your strength.’” ((Nehemiah 8:10))