“Isaiah looks at the sin-bearing servant of the Lord and has one thing to say to us: ‘Break forth into singing and cry aloud’ (54:1). 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.”
Ray Ortlund Jr., Isaiah: God Saves Sinners (Wheaton: Crossway, 2005), 363.
Ortlund has a joy-giving blog as well: Christ is Deeper Still. Take a visit.