Ray Ortlund on gladness in worship:

“Isaiah looks at the sin-bearing servant of the Lord (Is. 53) and has one thing to say to us: “Break forth into singing and cry aloud.” In other words, “Let joyful song explode out of you!” We resist that. Isaiah 54:1 may be one of the most disobeyed commands in the Bible. Our exaggerated sense of decorum is the last bastion of pride holding out against the gospel. Some churches make it a virtue. But God doesn’t. In his exuberance he’s creating a new world of boisterous happiness through Christ. We must rejoice with him, or we risk making our hearts impervious to salvation, because that holy but raucous joy is salvation.

When Jesus entered Jerusalem to the loud praises of his followers, the Pharisees didn’t like it one bit. But Jesus said, “If these were silent, the very stones would cry out” (Luke 19:40). Enthusiasm offends religious people, because breaking forth into singing and crying aloud entails loss of control. It brings us down to the level of children, even the vulgar who never learned their manners. So be it…Christianity throbs with holy joy for bad people. God made it that way.

The test of a church’s faith is not only the word in its creed but also the gladness in its worship. The gospel demands a carefree spirit. If we aren’t going to Hell anymore, if we stand to inherit every blessing Almighty God can think of, if nothing can stand in the way of our restored humanness because it’s all ours through the merit of Christ, the friend of sinners – if that can’t make us smile, what can?”

Raymond C. Ortlund, “Isaiah: God Saves Sinners,” in Preaching the Word Commentary, 363-364.