Karl Barth once commented that what matters most in the church's worship is not up-to-dateness but reformation. To be semper ecclesia reformanda does not mean to go with the time or let spirit of the age determine what is true or false. Nor does it mean to hide in the past. It means to carry out better than yesterday the task of singing a new song unto the Lord. "It means never to grow tired of returning not to the origin in time but to the origin in substance of the community."
Or as Pius XII said in his encyclical on worship, "To return in mind and heart to the well-springs of the sacred liturgy" In our uniquely ahistorical milieu, sometimes the oldest truth has a strikingly contemporary ring. I our historical study of the liturgy, we are continually impressed by much that we have lost. Many of the liturgical innovations that were made during the heat of Reformation polemical battles have left Protestants with a truncated and limited liturgical life...Those who do not know their history are doomed to repeat history's mistakes and to miss past glories in the narrowness of present expressions of faith. The historical norm reminds us that one of the best ways to arrive where we want to be today in worship is to first know where the church's worship has been before.
— Worship as Pastoral Care, William H. Willimon